diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
index 45527bec2f2ef..fbd67657e3b4c 100644
--- a/compiler/rustc_feature/src/unstable.rs
+++ b/compiler/rustc_feature/src/unstable.rs
@@ -449,7 +449,7 @@ declare_features! (
     /// Allows `dyn* Trait` objects.
     (incomplete, dyn_star, "1.65.0", Some(102425)),
     /// Uses generic effect parameters for ~const bounds
-    (unstable, effects, "1.72.0", Some(102090)),
+    (incomplete, effects, "1.72.0", Some(102090)),
     /// Allows exhaustive pattern matching on types that contain uninhabited types.
     (unstable, exhaustive_patterns, "1.13.0", Some(51085)),
     /// Allows explicit tail calls via `become` expression.
diff --git a/tests/ui/const-generics/const_trait_fn-issue-88433.rs b/tests/ui/const-generics/const_trait_fn-issue-88433.rs
index 89bcd54c46186..cd008aa2c9f2d 100644
--- a/tests/ui/const-generics/const_trait_fn-issue-88433.rs
+++ b/tests/ui/const-generics/const_trait_fn-issue-88433.rs
@@ -1,6 +1,6 @@
 //@ build-pass
 
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Func<T> {
diff --git a/tests/ui/const-generics/const_trait_fn-issue-88433.stderr b/tests/ui/const-generics/const_trait_fn-issue-88433.stderr
new file mode 100644
index 0000000000000..4e0d6370fbd50
--- /dev/null
+++ b/tests/ui/const-generics/const_trait_fn-issue-88433.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/const_trait_fn-issue-88433.rs:3:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/consts/auxiliary/closure-in-foreign-crate.rs b/tests/ui/consts/auxiliary/closure-in-foreign-crate.rs
index 8adf3ba433d96..eb58233d1b1f8 100644
--- a/tests/ui/consts/auxiliary/closure-in-foreign-crate.rs
+++ b/tests/ui/consts/auxiliary/closure-in-foreign-crate.rs
@@ -1,5 +1,5 @@
 #![crate_type = "lib"]
-#![feature(const_closures, const_trait_impl, effects)]
+#![feature(const_closures, const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 pub const fn test() {
     let cl = const || {};
diff --git a/tests/ui/consts/const-float-classify.stderr b/tests/ui/consts/const-float-classify.stderr
index 9ecd7b83681e1..1de27a072cf73 100644
--- a/tests/ui/consts/const-float-classify.stderr
+++ b/tests/ui/consts/const-float-classify.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/const-float-classify.rs:7:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: const `impl` for trait `PartialEq` which is not marked with `#[const_trait]`
   --> $DIR/const-float-classify.rs:12:12
    |
@@ -208,7 +217,7 @@ LL | impl const PartialEq<NonDet> for bool {
    |      unsatisfied trait bound introduced here
    = note: this error originates in the macro `const_assert` which comes from the expansion of the macro `suite` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 10 previous errors
+error: aborting due to 10 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0207, E0284.
 For more information about an error, try `rustc --explain E0207`.
diff --git a/tests/ui/consts/const_cmp_type_id.stderr b/tests/ui/consts/const_cmp_type_id.stderr
index f9628e5443b8d..e0e673d5fbdcf 100644
--- a/tests/ui/consts/const_cmp_type_id.stderr
+++ b/tests/ui/consts/const_cmp_type_id.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/const_cmp_type_id.rs:3:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0131]: `main` function is not allowed to have generic parameters
   --> $DIR/const_cmp_type_id.rs:7:14
    |
@@ -10,7 +19,7 @@ error[E0080]: evaluation of constant value failed
 LL |     const _A: bool = TypeId::of::<u8>() < TypeId::of::<u16>();
    |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ calling non-const function `<TypeId as PartialOrd>::lt`
 
-error: aborting due to 2 previous errors
+error: aborting due to 2 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0080, E0131.
 For more information about an error, try `rustc --explain E0080`.
diff --git a/tests/ui/consts/rustc-impl-const-stability.stderr b/tests/ui/consts/rustc-impl-const-stability.stderr
index ba8e6c1555ce2..250d1c3fc0553 100644
--- a/tests/ui/consts/rustc-impl-const-stability.stderr
+++ b/tests/ui/consts/rustc-impl-const-stability.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/rustc-impl-const-stability.rs:5:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: const `impl` for trait `Default` which is not marked with `#[const_trait]`
   --> $DIR/rustc-impl-const-stability.rs:15:12
    |
@@ -16,6 +25,6 @@ LL | impl const Default for Data {
    = note: expressions using a const parameter must map each value to a distinct output value
    = note: proving the result of expressions other than the parameter are unique is not supported
 
-error: aborting due to 2 previous errors
+error: aborting due to 2 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0207`.
diff --git a/tests/ui/parser/impls-nested-within-fns-semantic-1.rs b/tests/ui/parser/impls-nested-within-fns-semantic-1.rs
index 43530e41a66c1..0e95fc757f3e8 100644
--- a/tests/ui/parser/impls-nested-within-fns-semantic-1.rs
+++ b/tests/ui/parser/impls-nested-within-fns-semantic-1.rs
@@ -1,7 +1,7 @@
 // Regression test for part of issue #119924.
 //@ check-pass
 
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Trait {
diff --git a/tests/ui/parser/impls-nested-within-fns-semantic-1.stderr b/tests/ui/parser/impls-nested-within-fns-semantic-1.stderr
new file mode 100644
index 0000000000000..6670b3772db12
--- /dev/null
+++ b/tests/ui/parser/impls-nested-within-fns-semantic-1.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/impls-nested-within-fns-semantic-1.rs:4:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type-const-bound-usage-0.qualified.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type-const-bound-usage-0.qualified.stderr
index 62c8a442ab9bd..3aec4383eab3a 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type-const-bound-usage-0.qualified.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type-const-bound-usage-0.qualified.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/assoc-type-const-bound-usage-0.rs:6:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0277]: the trait bound `T: Trait` is not satisfied
   --> $DIR/assoc-type-const-bound-usage-0.rs:21:6
    |
@@ -9,6 +18,6 @@ help: consider further restricting this bound
 LL | const fn qualified<T: ~const Trait + Trait>() -> i32 {
    |                                    +++++++
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type-const-bound-usage-0.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type-const-bound-usage-0.rs
index 6b55e82629bbc..eecd6e6109c1e 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type-const-bound-usage-0.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type-const-bound-usage-0.rs
@@ -3,7 +3,7 @@
 //@[unqualified] check-pass
 //@[qualified] known-bug: unknown
 
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //[unqualified]~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Trait {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type-const-bound-usage-0.unqualified.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type-const-bound-usage-0.unqualified.stderr
new file mode 100644
index 0000000000000..3d592834600e0
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type-const-bound-usage-0.unqualified.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/assoc-type-const-bound-usage-0.rs:6:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type.rs
index 886fa6577d76c..645fff4e01471 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type.rs
@@ -1,5 +1,5 @@
 // FIXME(effects): Replace `Add` with `std::ops::Add` once the latter a `#[const_trait]` again.
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Add<Rhs = Self> {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type.stderr
index a9cae2a70be90..cc3abea25eb56 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/assoc-type.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/assoc-type.rs:2:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0277]: the trait bound `NonConstAdd: ~const Add` is not satisfied
   --> $DIR/assoc-type.rs:35:16
    |
@@ -11,6 +20,6 @@ note: required by a bound in `Foo::Bar`
 LL |     type Bar: ~const Add;
    |               ^^^^^^^^^^ required by this bound in `Foo::Bar`
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/auxiliary/cross-crate.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/auxiliary/cross-crate.rs
index f40dc27cb4c6f..62609384cff08 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/auxiliary/cross-crate.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/auxiliary/cross-crate.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 pub trait MyTrait {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/auxiliary/staged-api.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/auxiliary/staged-api.rs
index 687cb128b05be..fd4e1ff803da6 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/auxiliary/staged-api.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/auxiliary/staged-api.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 #![feature(staged_api)]
 #![stable(feature = "rust1", since = "1.0.0")]
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-const-trait-method-fail.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-const-trait-method-fail.rs
index 771c35cf6ab9d..bb9e9045f8fb5 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-const-trait-method-fail.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-const-trait-method-fail.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 pub trait Plus {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-const-trait-method-fail.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-const-trait-method-fail.stderr
index 93d520f29ef28..0e4dcf0f3026a 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-const-trait-method-fail.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-const-trait-method-fail.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/call-const-trait-method-fail.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0277]: the trait bound `u32: ~const Plus` is not satisfied
   --> $DIR/call-const-trait-method-fail.rs:25:5
    |
@@ -6,6 +15,6 @@ LL |     a.plus(b)
    |
    = help: the trait `Plus` is implemented for `u32`
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-chain.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-chain.stderr
index 4b0d304c5bee2..36c7a6544305b 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-chain.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-chain.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/call-generic-method-chain.rs:6:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: const `impl` for trait `PartialEq` which is not marked with `#[const_trait]`
   --> $DIR/call-generic-method-chain.rs:10:12
    |
@@ -56,7 +65,7 @@ LL | impl const PartialEq for S {
    |      |
    |      unsatisfied trait bound introduced here
 
-error: aborting due to 6 previous errors
+error: aborting due to 6 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0207, E0284.
 For more information about an error, try `rustc --explain E0207`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-dup-bound.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-dup-bound.stderr
index 69f7029516091..320e420b80a30 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-dup-bound.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-dup-bound.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/call-generic-method-dup-bound.rs:4:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: const `impl` for trait `PartialEq` which is not marked with `#[const_trait]`
   --> $DIR/call-generic-method-dup-bound.rs:8:12
    |
@@ -70,7 +79,7 @@ LL | impl const PartialEq for S {
    |      |
    |      unsatisfied trait bound introduced here
 
-error: aborting due to 7 previous errors
+error: aborting due to 7 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0207, E0284.
 For more information about an error, try `rustc --explain E0207`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-fail.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-fail.rs
index cc5f218ae2def..a9ed5a639d73a 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-fail.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-fail.rs
@@ -1,6 +1,6 @@
 //@ check-pass
 
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 pub const fn equals_self<T: PartialEq>(t: &T) -> bool {
     *t == *t
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-fail.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-fail.stderr
new file mode 100644
index 0000000000000..74b74052da079
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-fail.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/call-generic-method-fail.rs:3:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-nonconst.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-nonconst.rs
index 8d6176a5bace4..222bff2db8807 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-nonconst.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-nonconst.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 struct S;
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-nonconst.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-nonconst.stderr
index 3581b1fcd7dfb..fa59e5ee03dd0 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-nonconst.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-nonconst.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/call-generic-method-nonconst.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0277]: the trait bound `S: const Foo` is not satisfied
   --> $DIR/call-generic-method-nonconst.rs:23:34
    |
@@ -13,6 +22,6 @@ note: required by a bound in `equals_self`
 LL | const fn equals_self<T: ~const Foo>(t: &T) -> bool {
    |                         ^^^^^^^^^^ required by this bound in `equals_self`
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-pass.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-pass.stderr
index 1bba23e2892ee..6b9d290839e5f 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-pass.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/call-generic-method-pass.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/call-generic-method-pass.rs:6:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: const `impl` for trait `PartialEq` which is not marked with `#[const_trait]`
   --> $DIR/call-generic-method-pass.rs:10:12
    |
@@ -50,7 +59,7 @@ LL | impl const PartialEq for S {
    |      |
    |      unsatisfied trait bound introduced here
 
-error: aborting due to 5 previous errors
+error: aborting due to 5 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0207, E0284.
 For more information about an error, try `rustc --explain E0207`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-bounds-non-const-trait.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-bounds-non-const-trait.rs
index 3582e5e050c98..db446f8bc2eab 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-bounds-non-const-trait.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-bounds-non-const-trait.rs
@@ -1,5 +1,5 @@
 // Regression test for issue #117244.
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 trait NonConst {}
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-bounds-non-const-trait.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-bounds-non-const-trait.stderr
index 08954987d3192..d04e5490b7639 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-bounds-non-const-trait.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-bounds-non-const-trait.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/const-bounds-non-const-trait.rs:2:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: `~const` can only be applied to `#[const_trait]` traits
   --> $DIR/const-bounds-non-const-trait.rs:6:28
    |
@@ -10,5 +19,5 @@ error: `const` can only be applied to `#[const_trait]` traits
 LL | fn operate<T: const NonConst>() {}
    |                     ^^^^^^^^
 
-error: aborting due to 2 previous errors
+error: aborting due to 2 previous errors; 1 warning emitted
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.rs
index 4854f41bf04f4..a1710e6525292 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 struct S;
 #[const_trait]
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.stderr
index ae035b26ec582..d93327cea1b2c 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/const-check-fns-in-const-impl.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0015]: cannot call non-const fn `non_const` in constant functions
   --> $DIR/const-check-fns-in-const-impl.rs:12:16
    |
@@ -6,6 +15,6 @@ LL |     fn foo() { non_const() }
    |
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0015`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-default-method-bodies.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-default-method-bodies.rs
index be668b4f13a85..2fd58b05178c2 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-default-method-bodies.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-default-method-bodies.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait ConstDefaultFn: Sized {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-default-method-bodies.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-default-method-bodies.stderr
index f39e6dcadbaa6..8e04d0bd20da0 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-default-method-bodies.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-default-method-bodies.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/const-default-method-bodies.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0277]: the trait bound `NonConstImpl: ~const ConstDefaultFn` is not satisfied
   --> $DIR/const-default-method-bodies.rs:24:18
    |
@@ -6,6 +15,6 @@ LL |     NonConstImpl.a();
    |
    = help: the trait `ConstDefaultFn` is implemented for `NonConstImpl`
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-fns-are-early-bound.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-fns-are-early-bound.rs
index f6bba19a19eae..faa913c759884 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-fns-are-early-bound.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-fns-are-early-bound.rs
@@ -7,7 +7,7 @@
 #![feature(
     auto_traits,
     const_trait_impl,
-    effects,
+    effects,  //~ WARN the feature `effects` is incomplete
     lang_items,
     no_core,
     staged_api,
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-fns-are-early-bound.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-fns-are-early-bound.stderr
new file mode 100644
index 0000000000000..42b19fce28e9c
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-fns-are-early-bound.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/const-fns-are-early-bound.rs:10:5
+   |
+LL |     effects,
+   |     ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-impl-requires-const-trait.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-impl-requires-const-trait.stderr
index d20404e63b3fb..fb282d9ee2b47 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-impl-requires-const-trait.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-impl-requires-const-trait.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/const-impl-requires-const-trait.rs:3:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: const `impl` for trait `A` which is not marked with `#[const_trait]`
   --> $DIR/const-impl-requires-const-trait.rs:8:12
    |
@@ -19,6 +28,6 @@ LL | impl const A for () {}
    = note: expressions using a const parameter must map each value to a distinct output value
    = note: proving the result of expressions other than the parameter are unique is not supported
 
-error: aborting due to 2 previous errors
+error: aborting due to 2 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0207`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-trait-bounds-trait-objects.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-trait-bounds-trait-objects.rs
index 79719dae44f7c..8e71fa4d51902 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-trait-bounds-trait-objects.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-trait-bounds-trait-objects.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 //@ edition: 2021
 
 #[const_trait]
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-trait-bounds-trait-objects.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-trait-bounds-trait-objects.stderr
index 04c2dc2e2e0fd..7d774bef0e94a 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const-trait-bounds-trait-objects.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const-trait-bounds-trait-objects.stderr
@@ -26,5 +26,14 @@ LL | const fn take(_: &dyn ~const NonConst) {}
    |
    = note: trait objects cannot have `~const` trait bounds
 
-error: aborting due to 4 previous errors
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/const-trait-bounds-trait-objects.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error: aborting due to 4 previous errors; 1 warning emitted
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const_derives/derive-const-non-const-type.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/const_derives/derive-const-non-const-type.stderr
index 4b009446dbc00..1e091283510d6 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const_derives/derive-const-non-const-type.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const_derives/derive-const-non-const-type.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/derive-const-non-const-type.rs:2:26
+   |
+LL | #![feature(derive_const, effects)]
+   |                          ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: const `impl` for trait `Default` which is not marked with `#[const_trait]`
   --> $DIR/derive-const-non-const-type.rs:10:16
    |
@@ -13,6 +22,6 @@ error[E0207]: the const parameter `host` is not constrained by the impl trait, s
    = note: expressions using a const parameter must map each value to a distinct output value
    = note: proving the result of expressions other than the parameter are unique is not supported
 
-error: aborting due to 2 previous errors
+error: aborting due to 2 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0207`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const_derives/derive-const-use.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/const_derives/derive-const-use.stderr
index 82a971a36a8da..925b2c58ed77b 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const_derives/derive-const-use.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const_derives/derive-const-use.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/derive-const-use.rs:3:76
+   |
+LL | #![feature(const_trait_impl, const_cmp, const_default_impls, derive_const, effects)]
+   |                                                                            ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0635]: unknown feature `const_cmp`
   --> $DIR/derive-const-use.rs:3:30
    |
@@ -137,7 +146,7 @@ LL | impl const PartialEq for A {
    |      unsatisfied trait bound introduced here
    = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 14 previous errors
+error: aborting due to 14 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0207, E0284, E0635.
 For more information about an error, try `rustc --explain E0207`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/const_derives/derive-const-with-params.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/const_derives/derive-const-with-params.stderr
index 0e7d826db5435..5d3aa250d1854 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/const_derives/derive-const-with-params.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/const_derives/derive-const-with-params.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/derive-const-with-params.rs:5:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: const `impl` for trait `PartialEq` which is not marked with `#[const_trait]`
   --> $DIR/derive-const-with-params.rs:7:16
    |
@@ -34,7 +43,7 @@ LL | #[derive_const(PartialEq)]
    |                ^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
    = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 4 previous errors
+error: aborting due to 4 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0207, E0284.
 For more information about an error, try `rustc --explain E0207`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate-default-method-body-is-const.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate-default-method-body-is-const.rs
index 54e5c95c259ff..d8be8b13d0822 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate-default-method-body-is-const.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate-default-method-body-is-const.rs
@@ -3,7 +3,7 @@
 //
 //@ check-pass
 
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 //@ aux-build: cross-crate.rs
 extern crate cross_crate;
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate-default-method-body-is-const.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate-default-method-body-is-const.stderr
new file mode 100644
index 0000000000000..2f1e1e6b8d2b9
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate-default-method-body-is-const.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/cross-crate-default-method-body-is-const.rs:6:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.gated.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.gated.stderr
new file mode 100644
index 0000000000000..2ce29a74eaeb0
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.gated.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/cross-crate.rs:3:60
+   |
+LL | #![cfg_attr(any(gated, gatednc), feature(const_trait_impl, effects))]
+   |                                                            ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.gatednc.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.gatednc.stderr
index f0ac953fd5d20..ddb5b3c7c5078 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.gatednc.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.gatednc.stderr
@@ -1,11 +1,20 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/cross-crate.rs:3:60
+   |
+LL | #![cfg_attr(any(gated, gatednc), feature(const_trait_impl, effects))]
+   |                                                            ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0277]: the trait bound `cross_crate::NonConst: ~const cross_crate::MyTrait` is not satisfied
-  --> $DIR/cross-crate.rs:17:14
+  --> $DIR/cross-crate.rs:18:14
    |
 LL |     NonConst.func();
    |              ^^^^ the trait `~const cross_crate::MyTrait` is not implemented for `cross_crate::NonConst`
    |
    = help: the trait `cross_crate::MyTrait` is implemented for `cross_crate::NonConst`
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.rs
index 587dd70c18b29..04c101d0fc5fb 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.rs
@@ -1,6 +1,7 @@
 //@ revisions: stock gated stocknc gatednc
 //@ [gated] check-pass
 #![cfg_attr(any(gated, gatednc), feature(const_trait_impl, effects))]
+//[gated,gatednc]~^ WARN the feature `effects` is incomplete
 
 //@ aux-build: cross-crate.rs
 extern crate cross_crate;
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.stock.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.stock.stderr
index a0c50ac7e61b4..3df875057f2c8 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.stock.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.stock.stderr
@@ -1,5 +1,5 @@
 error[E0015]: cannot call non-const fn `<cross_crate::Const as cross_crate::MyTrait>::func` in constant functions
-  --> $DIR/cross-crate.rs:20:11
+  --> $DIR/cross-crate.rs:21:11
    |
 LL |     Const.func();
    |           ^^^^^^
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.stocknc.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.stocknc.stderr
index 312818ae6313e..e56a5e4165ce3 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.stocknc.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/cross-crate.stocknc.stderr
@@ -1,5 +1,5 @@
 error[E0015]: cannot call non-const fn `<cross_crate::NonConst as cross_crate::MyTrait>::func` in constant functions
-  --> $DIR/cross-crate.rs:17:14
+  --> $DIR/cross-crate.rs:18:14
    |
 LL |     NonConst.func();
    |              ^^^^^^
@@ -11,7 +11,7 @@ LL + #![feature(const_trait_impl)]
    |
 
 error[E0015]: cannot call non-const fn `<cross_crate::Const as cross_crate::MyTrait>::func` in constant functions
-  --> $DIR/cross-crate.rs:20:11
+  --> $DIR/cross-crate.rs:21:11
    |
 LL |     Const.func();
    |           ^^^^^^
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.rs
index da27724007d27..64f23824b397d 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 pub trait Tr {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.stderr
index 29db6109a98c4..67a936d0882f4 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/default-method-body-is-const-same-trait-ck.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0277]: the trait bound `(): ~const Tr` is not satisfied
   --> $DIR/default-method-body-is-const-same-trait-ck.rs:8:12
    |
@@ -6,6 +15,6 @@ LL |         ().a()
    |
    = help: the trait `Tr` is implemented for `()`
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/do-not-const-check-override.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/do-not-const-check-override.rs
index 8b51f65fd04ff..be5e66478dfaf 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/do-not-const-check-override.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/do-not-const-check-override.rs
@@ -1,5 +1,5 @@
 //@ check-pass
-#![feature(const_trait_impl, rustc_attrs, effects)]
+#![feature(const_trait_impl, rustc_attrs, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Foo {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/do-not-const-check-override.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/do-not-const-check-override.stderr
new file mode 100644
index 0000000000000..4be1160b58cb2
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/do-not-const-check-override.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/do-not-const-check-override.rs:2:43
+   |
+LL | #![feature(const_trait_impl, rustc_attrs, effects)]
+   |                                           ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/auxiliary/cross-crate.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/auxiliary/cross-crate.rs
index a74c50cc8fa47..5c32eee8737e8 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/auxiliary/cross-crate.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/auxiliary/cross-crate.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 pub const fn foo() {}
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/effect-param-infer.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/effect-param-infer.rs
index d35e9bb7f1efd..b354591e0070f 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/effect-param-infer.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/effect-param-infer.rs
@@ -3,7 +3,7 @@
 //
 //@ check-pass
 
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 pub trait Foo<Rhs: ?Sized = Self> {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/effect-param-infer.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/effect-param-infer.stderr
new file mode 100644
index 0000000000000..7ceb3669e5983
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/effect-param-infer.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/effect-param-infer.rs:6:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/fallback.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/fallback.rs
index aa75aa9c989d6..d949e4b829fc4 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/fallback.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/fallback.rs
@@ -1,6 +1,6 @@
 //@ check-pass
 
-#![feature(effects)]
+#![feature(effects)] //~ WARN the feature `effects` is incomplete
 
 pub const fn owo() {}
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/fallback.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/fallback.stderr
new file mode 100644
index 0000000000000..f7d5de829b200
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/fallback.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/fallback.rs:3:12
+   |
+LL | #![feature(effects)]
+   |            ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/helloworld.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/helloworld.rs
index 502062a559c11..eed8cdc447c55 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/helloworld.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/helloworld.rs
@@ -3,7 +3,12 @@
 // gate-test-effects
 // ^ effects doesn't have a gate so we will trick tidy into thinking this is a gate test
 
-#![feature(const_trait_impl, effects, core_intrinsics, const_eval_select)]
+#![feature(
+    const_trait_impl,
+    effects, //~ WARN the feature `effects` is incomplete
+    core_intrinsics,
+    const_eval_select
+)]
 
 // ensure we are passing in the correct host effect in always const contexts.
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/helloworld.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/helloworld.stderr
new file mode 100644
index 0000000000000..8719c5cbcef0f
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/helloworld.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/helloworld.rs:8:5
+   |
+LL |     effects,
+   |     ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/ice-112822-expected-type-for-param.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/ice-112822-expected-type-for-param.rs
index 306770fc245b9..9a9016de3a0d9 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/ice-112822-expected-type-for-param.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/ice-112822-expected-type-for-param.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 const fn test() -> impl ~const Fn() {
     //~^ ERROR `~const` can only be applied to `#[const_trait]` traits
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/ice-112822-expected-type-for-param.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/ice-112822-expected-type-for-param.stderr
index e15f697b29e9f..3f0ed13d665f8 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/ice-112822-expected-type-for-param.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/ice-112822-expected-type-for-param.stderr
@@ -8,6 +8,15 @@ LL |     const move || {
    = help: add `#![feature(const_closures)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/ice-112822-expected-type-for-param.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: `~const` can only be applied to `#[const_trait]` traits
   --> $DIR/ice-112822-expected-type-for-param.rs:3:32
    |
@@ -31,7 +40,7 @@ LL |                 assert_eq!(first, &b'f');
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
    = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 4 previous errors
+error: aborting due to 4 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0015, E0658.
 For more information about an error, try `rustc --explain E0015`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/infer-fallback.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/infer-fallback.rs
index 85aabe46640e7..ff3a27c3ee479 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/infer-fallback.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/infer-fallback.rs
@@ -1,5 +1,5 @@
 //@ check-pass
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 const fn a() {}
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/infer-fallback.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/infer-fallback.stderr
new file mode 100644
index 0000000000000..49c7d3958466a
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/infer-fallback.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/infer-fallback.rs:2:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/minicore.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/minicore.stderr
index d9450216dacb5..e4a5f3686084e 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/minicore.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/minicore.stderr
@@ -1,9 +1,18 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/minicore.rs:8:30
+   |
+LL | #![feature(const_trait_impl, effects, const_mut_refs)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0094]: intrinsic has wrong number of const parameters: found 1, expected 0
   --> $DIR/minicore.rs:517:27
    |
 LL | const fn const_eval_select<ARG: Tuple, F, G, RET>(
    |                           ^^^^^^^^^^^^^^^^^^^^^^^ expected 0 const parameters
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0094`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/no-explicit-const-params.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/no-explicit-const-params.rs
index 929da1ca8fa99..84f5f2803e156 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/no-explicit-const-params.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/no-explicit-const-params.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 const fn foo() {}
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/no-explicit-const-params.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/no-explicit-const-params.stderr
index 0745d0304b9e6..39aa5825611f3 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/no-explicit-const-params.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/no-explicit-const-params.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/no-explicit-const-params.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0107]: function takes 0 generic arguments but 1 generic argument was supplied
   --> $DIR/no-explicit-const-params.rs:22:5
    |
@@ -63,7 +72,7 @@ note: trait defined here, with 0 generic parameters
 LL | trait Bar {
    |       ^^^
 
-error: aborting due to 5 previous errors
+error: aborting due to 5 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0107, E0308.
 For more information about an error, try `rustc --explain E0107`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/project.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/project.stderr
index eac3ee9e4e22b..ab5f7b55a4e47 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/project.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/project.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/project.rs:4:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0277]: the trait bound `Self: Uwu` is not satisfied
   --> $DIR/project.rs:12:1
    |
@@ -60,6 +69,6 @@ help: consider further restricting `Self`
 LL | pub trait Uwu: Owo + Uwu {
    |                    +++++
 
-error: aborting due to 5 previous errors
+error: aborting due to 5 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/span-bug-issue-121418.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/span-bug-issue-121418.rs
index 7bead45b35ab7..987a162cd6cae 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/span-bug-issue-121418.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/span-bug-issue-121418.rs
@@ -1,5 +1,5 @@
 #![feature(const_trait_impl)]
-#![feature(effects)]
+#![feature(effects)] //~ WARN the feature `effects` is incomplete
 
 struct S;
 trait T {}
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/span-bug-issue-121418.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/span-bug-issue-121418.stderr
index 3ff1efb59883d..f24d7c7a16017 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/span-bug-issue-121418.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/span-bug-issue-121418.stderr
@@ -8,6 +8,15 @@ LL | impl const dyn T {
    |
    = note: only trait implementations may be annotated with `const`
 
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/span-bug-issue-121418.rs:2:12
+   |
+LL | #![feature(effects)]
+   |            ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0207]: the const parameter `host` is not constrained by the impl trait, self type, or predicates
   --> $DIR/span-bug-issue-121418.rs:7:6
    |
@@ -39,7 +48,7 @@ note: required because it appears within the type `Mutex<(dyn T + 'static)>`
   --> $SRC_DIR/std/src/sync/mutex.rs:LL:COL
    = note: the return type of a function must have a statically known size
 
-error: aborting due to 4 previous errors
+error: aborting due to 4 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0207, E0277, E0308.
 For more information about an error, try `rustc --explain E0207`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/spec-effectvar-ice.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/spec-effectvar-ice.rs
index 6b5ba5bb6241d..00465b0f53d5a 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/spec-effectvar-ice.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/spec-effectvar-ice.rs
@@ -1,7 +1,7 @@
 //@ check-fail
 // Fixes #119830
 
-#![feature(effects)]
+#![feature(effects)] //~ WARN the feature `effects` is incomplete
 #![feature(min_specialization)]
 #![feature(const_trait_impl)]
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/spec-effectvar-ice.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/spec-effectvar-ice.stderr
index 70dd0350dc427..8d69151bf74c3 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/spec-effectvar-ice.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/spec-effectvar-ice.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/spec-effectvar-ice.rs:4:12
+   |
+LL | #![feature(effects)]
+   |            ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: const `impl` for trait `Foo` which is not marked with `#[const_trait]`
   --> $DIR/spec-effectvar-ice.rs:12:15
    |
@@ -55,7 +64,7 @@ LL | impl<T> const Foo for T where T: const Specialize {}
    = note: expressions using a const parameter must map each value to a distinct output value
    = note: proving the result of expressions other than the parameter are unique is not supported
 
-error: aborting due to 6 previous errors
+error: aborting due to 6 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0119, E0207.
 For more information about an error, try `rustc --explain E0119`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/trait-fn-const.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/trait-fn-const.rs
index 891e87d3b97d4..d63dbfbf57d4a 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/trait-fn-const.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/trait-fn-const.rs
@@ -1,5 +1,5 @@
 // Regression test for issue #113378.
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Trait {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/trait-fn-const.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/trait-fn-const.stderr
index 4d0b03046d27d..33914cb306dc6 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/trait-fn-const.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/effects/trait-fn-const.stderr
@@ -54,6 +54,15 @@ LL + #[const_trait]
 LL | trait NonConst {
    |
 
-error: aborting due to 4 previous errors
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/trait-fn-const.rs:2:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error: aborting due to 4 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0379`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/hir-const-check.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/hir-const-check.rs
index 426534deb67e7..f5fb0fd516a71 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/hir-const-check.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/hir-const-check.rs
@@ -1,6 +1,6 @@
 // Regression test for #69615.
 
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 pub trait MyTrait {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/hir-const-check.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/hir-const-check.stderr
index 5b14ef46d25d3..416ba248a5f31 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/hir-const-check.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/hir-const-check.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/hir-const-check.rs:3:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0658]: `?` is not allowed in a `const fn`
   --> $DIR/hir-const-check.rs:12:9
    |
@@ -8,6 +17,6 @@ LL |         Some(())?;
    = help: add `#![feature(const_try)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0658`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.rs
index 482a1aef06b57..ab46d49073c7a 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.rs
@@ -1,5 +1,5 @@
 //@ edition: 2021
-#![feature(effects)]
+#![feature(effects)] //~ WARN the feature `effects` is incomplete
 
 trait MyTrait {}
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.stderr
index 1110b799c6c47..011232f30b8a6 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-120503-async-const-method.stderr
@@ -46,6 +46,15 @@ LL | |
 LL | |     }
    | |_____^ not a member of trait `MyTrait`
 
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/ice-120503-async-const-method.rs:2:12
+   |
+LL | #![feature(effects)]
+   |            ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0425]: cannot find function `main8` in this scope
   --> $DIR/ice-120503-async-const-method.rs:13:9
    |
@@ -86,7 +95,7 @@ LL |     async const fn bar(&self) {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
-error: aborting due to 6 previous errors
+error: aborting due to 6 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0379, E0391, E0407, E0425.
 For more information about an error, try `rustc --explain E0379`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-121536-const-method.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-121536-const-method.rs
index fee0a2073e8dd..a01329278d78a 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-121536-const-method.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-121536-const-method.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 pub struct Vec3;
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-121536-const-method.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-121536-const-method.stderr
index 408958abf6307..4fe88f263c81b 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-121536-const-method.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/ice-121536-const-method.stderr
@@ -14,6 +14,15 @@ help: ... and declare the impl to be const instead
 LL | impl const Add for Vec3 {
    |      +++++
 
-error: aborting due to 1 previous error
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/ice-121536-const-method.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0379`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/issue-79450.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/issue-79450.rs
index 269fd87ba0d49..36c82dfe68485 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/issue-79450.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/issue-79450.rs
@@ -1,5 +1,5 @@
 #![feature(const_fmt_arguments_new)]
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Tr {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/issue-79450.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/issue-79450.stderr
index 85996c212118f..9da31486faaff 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/issue-79450.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/issue-79450.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/issue-79450.rs:2:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0015]: cannot call non-const fn `_print` in constant functions
   --> $DIR/issue-79450.rs:9:9
    |
@@ -7,6 +16,6 @@ LL |         println!("lul");
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
    = note: this error originates in the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0015`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-const-specialized.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-const-specialized.rs
index 6153e2770a4b0..c653e62032e6e 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-const-specialized.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-const-specialized.rs
@@ -3,7 +3,7 @@
 
 //@ run-pass
 
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 #![feature(min_specialization)]
 
 #[const_trait]
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-const-specialized.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-const-specialized.stderr
new file mode 100644
index 0000000000000..f533fb61aad75
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-const-specialized.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/const-default-const-specialized.rs:6:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-impl-non-const-specialized-impl.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-impl-non-const-specialized-impl.rs
index 9a93d01ed06e9..40fc3b17ae48b 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-impl-non-const-specialized-impl.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-impl-non-const-specialized-impl.rs
@@ -1,6 +1,6 @@
 // Tests that specializing trait impls must be at least as const as the default impl.
 
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 #![feature(min_specialization)]
 
 #[const_trait]
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-impl-non-const-specialized-impl.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-impl-non-const-specialized-impl.stderr
index e356621ba47ed..363fbee1f8bfb 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-impl-non-const-specialized-impl.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-impl-non-const-specialized-impl.stderr
@@ -1,8 +1,17 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/const-default-impl-non-const-specialized-impl.rs:3:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: cannot specialize on const impl with non-const impl
   --> $DIR/const-default-impl-non-const-specialized-impl.rs:19:1
    |
 LL | impl Value for FortyTwo {
    | ^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/non-const-default-const-specialized.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/non-const-default-const-specialized.stderr
index 68eac990aaab0..bcccc855aab52 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/non-const-default-const-specialized.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/non-const-default-const-specialized.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/non-const-default-const-specialized.rs:6:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0119]: conflicting implementations of trait `Value` for type `FortyTwo`
   --> $DIR/non-const-default-const-specialized.rs:27:1
    |
@@ -7,6 +16,6 @@ LL | impl<T> Value for T {
 LL | impl const Value for FortyTwo {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `FortyTwo`
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0119`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness-2.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness-2.stderr
index e5b9493b3ce11..7404b6a8b11f2 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness-2.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness-2.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/specializing-constness-2.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects, min_specialization, rustc_attrs)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0119]: conflicting implementations of trait `A`
   --> $DIR/specializing-constness-2.rs:20:1
    |
@@ -16,7 +25,7 @@ LL |     <T as A>::a();
    = note: expected constant `host`
               found constant `true`
 
-error: aborting due to 2 previous errors
+error: aborting due to 2 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0119, E0308.
 For more information about an error, try `rustc --explain E0119`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness.rs
index 7206a89e5c58c..3aabaf137d54c 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects, min_specialization, rustc_attrs)]
+#![feature(const_trait_impl, effects, min_specialization, rustc_attrs)] //~ WARN the feature `effects` is incomplete
 
 #[rustc_specialization_trait]
 #[const_trait]
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness.stderr
index 21e21c2cb71aa..226295bf949df 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/specializing-constness.stderr
@@ -1,8 +1,17 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/specializing-constness.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects, min_specialization, rustc_attrs)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: cannot specialize on const impl with non-const impl
   --> $DIR/specializing-constness.rs:23:1
    |
 LL | impl<T: Spec + Sup> A for T {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/staged-api.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/staged-api.rs
index 31ca9419589cb..460c2ef617438 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/staged-api.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/staged-api.rs
@@ -1,7 +1,7 @@
 //@ revisions: stable unstable
 
 #![cfg_attr(unstable, feature(unstable))] // The feature from the ./auxiliary/staged-api.rs file.
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 #![feature(staged_api)]
 #![stable(feature = "rust1", since = "1.0.0")]
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/staged-api.stable.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/staged-api.stable.stderr
index 9512953977003..0604b22ecbb3e 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/staged-api.stable.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/staged-api.stable.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/staged-api.rs:4:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: trait implementations cannot be const stable yet
   --> $DIR/staged-api.rs:19:1
    |
@@ -45,5 +54,5 @@ LL |     Unstable::func();
    |
    = help: const-stable functions can only call other const-stable functions
 
-error: aborting due to 5 previous errors
+error: aborting due to 5 previous errors; 1 warning emitted
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/staged-api.unstable.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/staged-api.unstable.stderr
index c9ca15d5b565f..b53e7b6f6acec 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/staged-api.unstable.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/staged-api.unstable.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/staged-api.rs:4:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: `<Foo as staged_api::MyTrait>::func` is not yet stable as a const fn
   --> $DIR/staged-api.rs:34:5
    |
@@ -38,5 +47,5 @@ LL |     const_context_not_const_stable()
    |
    = help: const-stable functions can only call other const-stable functions
 
-error: aborting due to 5 previous errors
+error: aborting due to 5 previous errors; 1 warning emitted
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.nn.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.nn.stderr
index ac25812c42dfb..3a36a5b750932 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.nn.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.nn.stderr
@@ -10,6 +10,15 @@ note: this trait is not a `#[const_trait]`, so it cannot have `~const` trait bou
 LL | trait Bar: ~const Foo {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^
 
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/super-traits-fail-2.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: `~const` can only be applied to `#[const_trait]` traits
   --> $DIR/super-traits-fail-2.rs:10:19
    |
@@ -32,5 +41,5 @@ LL | trait Bar: ~const Foo {}
    |
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
-error: aborting due to 4 previous errors
+error: aborting due to 4 previous errors; 1 warning emitted
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.ny.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.ny.stderr
index 5273f7e48eb8a..beb931570cb85 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.ny.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.ny.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/super-traits-fail-2.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: `~const` can only be applied to `#[const_trait]` traits
   --> $DIR/super-traits-fail-2.rs:10:19
    |
@@ -20,5 +29,5 @@ LL | trait Bar: ~const Foo {}
    |
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
-error: aborting due to 3 previous errors
+error: aborting due to 3 previous errors; 1 warning emitted
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.rs
index 6d57a4f5798f6..2f26eebbe32f9 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 //@ revisions: yy yn ny nn
 
 #[cfg_attr(any(yy, yn), const_trait)]
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.yn.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.yn.stderr
index 53445d2559036..f96e6fb4ae468 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.yn.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.yn.stderr
@@ -10,6 +10,15 @@ note: this trait is not a `#[const_trait]`, so it cannot have `~const` trait bou
 LL | trait Bar: ~const Foo {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^
 
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/super-traits-fail-2.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0308]: mismatched types
   --> $DIR/super-traits-fail-2.rs:17:5
    |
@@ -19,6 +28,6 @@ LL |     x.a();
    = note: expected constant `host`
               found constant `true`
 
-error: aborting due to 2 previous errors
+error: aborting due to 2 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.yy.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.yy.stderr
index 681647945d0a7..ffc259e590e80 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.yy.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-2.yy.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/super-traits-fail-2.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0308]: mismatched types
   --> $DIR/super-traits-fail-2.rs:17:5
    |
@@ -7,6 +16,6 @@ LL |     x.a();
    = note: expected constant `host`
               found constant `true`
 
-error: aborting due to 1 previous error
+error: aborting due to 1 previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.nn.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.nn.stderr
index 77aee6a8bb8f8..cde4b1ff77f35 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.nn.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.nn.stderr
@@ -10,6 +10,15 @@ note: this trait is not a `#[const_trait]`, so it cannot have `~const` trait bou
 LL | trait Bar: ~const Foo {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^
 
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/super-traits-fail-3.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: `~const` can only be applied to `#[const_trait]` traits
   --> $DIR/super-traits-fail-3.rs:12:19
    |
@@ -38,5 +47,5 @@ error: `~const` can only be applied to `#[const_trait]` traits
 LL | const fn foo<T: ~const Bar>(x: &T) {
    |                        ^^^
 
-error: aborting due to 5 previous errors
+error: aborting due to 5 previous errors; 1 warning emitted
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.ny.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.ny.stderr
index f737cb243df41..6f1840181481c 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.ny.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.ny.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/super-traits-fail-3.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: `~const` can only be applied to `#[const_trait]` traits
   --> $DIR/super-traits-fail-3.rs:12:19
    |
@@ -20,5 +29,5 @@ LL | trait Bar: ~const Foo {}
    |
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
-error: aborting due to 3 previous errors
+error: aborting due to 3 previous errors; 1 warning emitted
 
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.rs
index 1e02a13510013..f7e85902a41b2 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.rs
@@ -1,4 +1,4 @@
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 //@ revisions: yy yn ny nn
 //@[yy] check-pass
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.yn.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.yn.stderr
index de7a11cf15511..b0a3b39631dca 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.yn.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.yn.stderr
@@ -10,6 +10,15 @@ note: this trait is not a `#[const_trait]`, so it cannot have `~const` trait bou
 LL | trait Bar: ~const Foo {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^
 
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/super-traits-fail-3.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: `~const` can only be applied to `#[const_trait]` traits
   --> $DIR/super-traits-fail-3.rs:18:24
    |
@@ -25,6 +34,6 @@ LL |     x.a();
    = note: expected constant `host`
               found constant `true`
 
-error: aborting due to 3 previous errors
+error: aborting due to 3 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.yy.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.yy.stderr
new file mode 100644
index 0000000000000..e354c66919ec6
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits-fail-3.yy.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/super-traits-fail-3.rs:1:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits.rs
index 0515380564d4e..cfbb8e9f6be57 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits.rs
@@ -1,5 +1,5 @@
 //@ check-pass
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Foo {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits.stderr
new file mode 100644
index 0000000000000..2ff1a880d84f0
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/super-traits.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/super-traits.rs:2:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-assoc-fn-in-trait-impl.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-assoc-fn-in-trait-impl.rs
index ad0f10f7ee832..86a2bbe35ed7d 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-assoc-fn-in-trait-impl.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-assoc-fn-in-trait-impl.rs
@@ -1,7 +1,7 @@
 // Regression test for issue #119700.
 //@ check-pass
 
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Main {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-assoc-fn-in-trait-impl.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-assoc-fn-in-trait-impl.stderr
new file mode 100644
index 0000000000000..70019ce57f29e
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-assoc-fn-in-trait-impl.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/tilde-const-assoc-fn-in-trait-impl.rs:4:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-inherent-assoc-const-fn.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-inherent-assoc-const-fn.rs
index 5c8f5f4db3b54..0f5729e3daf62 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-inherent-assoc-const-fn.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-inherent-assoc-const-fn.rs
@@ -1,5 +1,5 @@
 //@ check-pass
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Foo {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-inherent-assoc-const-fn.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-inherent-assoc-const-fn.stderr
new file mode 100644
index 0000000000000..4ec8dac1f0d3a
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-inherent-assoc-const-fn.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/tilde-const-inherent-assoc-const-fn.rs:2:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-trait-assoc-tys.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-trait-assoc-tys.rs
index b400678308291..c2d3b2036c638 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-trait-assoc-tys.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-trait-assoc-tys.rs
@@ -1,5 +1,5 @@
 //@ check-pass
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Trait {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-trait-assoc-tys.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-trait-assoc-tys.stderr
new file mode 100644
index 0000000000000..1ead23d5c2c1d
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-trait-assoc-tys.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/tilde-const-trait-assoc-tys.rs:2:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-default-body-stability.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-default-body-stability.stderr
index b58af6bb9d007..adb1b01f08704 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-default-body-stability.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-default-body-stability.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/trait-default-body-stability.rs:4:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: const `impl` for trait `Try` which is not marked with `#[const_trait]`
   --> $DIR/trait-default-body-stability.rs:18:12
    |
@@ -121,7 +130,7 @@ LL | impl const Try for T {
    |      unsatisfied trait bound introduced here
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
-error: aborting due to 10 previous errors
+error: aborting due to 10 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0207, E0284.
 For more information about an error, try `rustc --explain E0207`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-const.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-const.stderr
index 0141dcfb06f6b..95c32b12241c9 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-const.stderr
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-const.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/trait-where-clause-const.rs:7:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error[E0277]: the trait bound `T: ~const Bar` is not satisfied
   --> $DIR/trait-where-clause-const.rs:21:5
    |
@@ -30,6 +39,6 @@ help: consider further restricting this bound
 LL | const fn test1<T: ~const Foo + Bar + ~const Bar>() {
    |                                    ++++++++++++
 
-error: aborting due to 2 previous errors
+error: aborting due to 2 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-run.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-run.rs
index 65e605a4a2fec..afc5b1c836993 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-run.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-run.rs
@@ -1,6 +1,6 @@
 //@ run-pass
 
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Bar {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-run.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-run.stderr
new file mode 100644
index 0000000000000..aef4f569d5e11
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-run.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/trait-where-clause-run.rs:3:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-self-referential.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-self-referential.rs
index 18d0267fed365..59ddc2f748ede 100644
--- a/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-self-referential.rs
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-self-referential.rs
@@ -1,6 +1,6 @@
 //@ check-pass
 
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 
 #[const_trait]
 trait Foo {
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-self-referential.stderr b/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-self-referential.stderr
new file mode 100644
index 0000000000000..6e9e948e45cd3
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause-self-referential.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/trait-where-clause-self-referential.rs:3:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/stability-attribute/missing-const-stability.rs b/tests/ui/stability-attribute/missing-const-stability.rs
index 621e857624910..62bb0239168e0 100644
--- a/tests/ui/stability-attribute/missing-const-stability.rs
+++ b/tests/ui/stability-attribute/missing-const-stability.rs
@@ -1,5 +1,5 @@
 #![feature(staged_api)]
-#![feature(const_trait_impl, effects)]
+#![feature(const_trait_impl, effects)] //~ WARN the feature `effects` is incomplete
 #![stable(feature = "stable", since = "1.0.0")]
 
 #[stable(feature = "stable", since = "1.0.0")]
diff --git a/tests/ui/stability-attribute/missing-const-stability.stderr b/tests/ui/stability-attribute/missing-const-stability.stderr
index 4cfbe152891ba..4e488124fe394 100644
--- a/tests/ui/stability-attribute/missing-const-stability.stderr
+++ b/tests/ui/stability-attribute/missing-const-stability.stderr
@@ -1,3 +1,12 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/missing-const-stability.rs:2:30
+   |
+LL | #![feature(const_trait_impl, effects)]
+   |                              ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
 error: function has missing const stability attribute
   --> $DIR/missing-const-stability.rs:6:1
    |
@@ -19,5 +28,5 @@ error: associated function has missing const stability attribute
 LL |     pub const fn foo() {}
    |     ^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 3 previous errors
+error: aborting due to 3 previous errors; 1 warning emitted
 
diff --git a/tests/ui/traits/next-solver/canonical/effect-var.rs b/tests/ui/traits/next-solver/canonical/effect-var.rs
index 6d0f09bb9be63..d1e3e18cdc807 100644
--- a/tests/ui/traits/next-solver/canonical/effect-var.rs
+++ b/tests/ui/traits/next-solver/canonical/effect-var.rs
@@ -1,7 +1,7 @@
 //@ compile-flags: -Znext-solver
 //@ check-pass
 
-#![feature(effects)]
+#![feature(effects)] //~ WARN the feature `effects` is incomplete
 #![feature(const_trait_impl)]
 
 #[const_trait]
diff --git a/tests/ui/traits/next-solver/canonical/effect-var.stderr b/tests/ui/traits/next-solver/canonical/effect-var.stderr
new file mode 100644
index 0000000000000..994228c51e5e1
--- /dev/null
+++ b/tests/ui/traits/next-solver/canonical/effect-var.stderr
@@ -0,0 +1,11 @@
+warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/effect-var.rs:4:12
+   |
+LL | #![feature(effects)]
+   |            ^^^^^^^
+   |
+   = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+