Cannot build code containing debug.SetGCPercent() for Android ARM

[evanw]

What version of Go are you using (go version)?

$ go version
go version go1.17 darwin/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/evan/Library/Caches/go-build"
GOENV="/Users/evan/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/evan/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/evan/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GOVCS=""
GOVERSION="go1.17"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/evan/dev/esbuild/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/j6/np400cw17sz0n5ljd67byrzw0000gn/T/go-build3774117208=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

I tried to build the following program for Android ARM:

package main

import "runtime/debug"

func main() {
	debug.SetGCPercent(-1)
}

This is a reduced test case from a real program: https://github.com/evanw/esbuild. I am able to cross-compile this program for all platforms except for Android ARM. More context is here: evanw/esbuild#1578.

What did you expect to see?

I expected the build to succeed.

What did you see instead?

The build fails with a cgo-related error. The build also fails if cgo is enabled:

$ GOOS="android" GOARCH="arm" go build main.go
# command-line-arguments
loadinternal: cannot find runtime/cgo
/usr/local/go/pkg/tool/darwin_amd64/link: running clang failed: exit status 1
ld: unknown option: -z
clang: error: linker command failed with exit code 1 (use -v to see invocation)

$ CGO_ENABLED=1 GOOS="android" GOARCH="arm" go build main.go
# runtime/cgo
clang: error: argument unused during compilation: '-marm' [-Werror,-Wunused-command-line-argument]

Building the same program for Android ARM64 works fine:

$ GOOS="android" GOARCH="arm64" go build main.go && file main
main: ELF 64-bit LSB pie executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /system/bin/linker64, Go BuildID=alvXLw57shg5zRLjPYoO/GyVC8TDUJ07MNhoXCsu-/nzi6B7uKoZ53M53L4eR-/0JYttdF-za9eeF0oEvPR, not stripped

[cherrymui]

To cross compile, you need to set CC to a C cross compiler targeting Android ARM.

Currently we support internal linking for Android ARM64, but not for Android ARM(32). So you'll need a C toolchain to build. Thanks.