cmd/go: TestCrossPackageTests fails on musl (Alpine Linux Edge)

[nmeum]

This is a follow up to #39343 where I already briefly mentioned this problem. This issue is probably related to musl libc I can reliably reproduce it on Alpine Linux which uses musl.

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

$ go version
go version go1.14.3 linux/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="/home/soeren/.cache/go-build"
GOENV="/home/soeren/.config/go/env"
GOEXE=""
GOFLAGS="-buildmode=pie"
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/soeren/src/go"
GOPRIVATE=""
GOPROXY="direct"
GOROOT="/usr/lib/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build802004994=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Started the TestCrossPackageTests from misc/cgo/test/pkg_test.go:

misc/cgo/test$ go test -run TestCrossPackageTests

What did you expect to see?

A successful test run.

What did you see instead?

An error message:

--- FAIL: TestCrossPackageTests (1.95s)
    pkg_test.go:67: go test: exit status 1
        --- FAIL: Test9400 (0.00s)
            issue9400_linux.go:55: entry 804 of test pattern is wrong; 0x7fc60b3b0cf4 != 0x123456789abcdef
        FAIL
        exit status 1
        FAIL	cgotest	0.005s
FAIL
exit status 1
FAIL	misc/cgo/test	1.958s