fix: put checkout_cores test behind a single-threaded feature (#1383)

* fix: put checkout_cores test behind a single-threaded feature
* feat: add checkout_cores test to CI, run single threaded
* fix: correct arg ordering typo

.circleci/config.yml

@@ -147,6 +147,7 @@ jobs:
             ulimit -u 20000
             ulimit -n 20000
             cargo +<< pipeline.parameters.nightly-toolchain >> -Zpackage-features test --all --verbose --release lifecycle -- --ignored --nocapture
+            cargo +<< pipeline.parameters.nightly-toolchain >> -Zpackage-features test -p storage-proofs-porep --features single-threaded --release checkout_cores -- --test-threads=1
           no_output_timeout: 30m
           environment:
             RUST_TEST_THREADS: 1

storage-proofs/porep/Cargo.toml

@@ -53,6 +53,7 @@ default = ["pairing", "gpu"]
 gpu = ["storage-proofs-core/gpu", "filecoin-hashers/gpu"]
 pairing = ["storage-proofs-core/pairing", "bellperson/pairing", "neptune/pairing", "filecoin-hashers/pairing"]
 blst = ["storage-proofs-core/blst", "bellperson/blst", "neptune/blst", "filecoin-hashers/blst"]
+single-threaded = []
 
 [[bench]]
 name = "encode"

storage-proofs/porep/src/stacked/vanilla/cores.rs

@@ -201,6 +201,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg(feature = "single-threaded")]
     fn test_checkout_cores() {
         let checkout1 = checkout_core_group();
         dbg!(&checkout1);

storage-proofs/porep/src/stacked/vanilla/proof.rs

@@ -60,7 +60,7 @@ pub const TOTAL_PARENTS: usize = 37;
 lazy_static! {
     /// Ensure that only one `TreeBuilder` or `ColumnTreeBuilder` uses the GPU at a time.
     /// Curently, this is accomplished by only instantiating at most one at a time.
-    /// It might be possible relax this constraint, but in that case, only one builder
+    /// It might be possible to relax this constraint, but in that case, only one builder
     /// should actually be active at any given time, so the mutex should still be used.
     static ref GPU_LOCK: Mutex<()> = Mutex::new(());
 }