@cznic,

I guess that it happens when CGO_ENABLED=0 and using go build --tags cgo, not only on os/user package but net package, right?

It's triggered by a 3rd party package loader (work in progress), which does not support CGO, so the cgo tag is undefined.

Do you need a exact reproduction case/steps? I can prepare that, it's just it involves unfinished/unstable stuff.

OTOH, CGO_ENABLED= 0 ./all.bash should do the same, in theory, and I did not try that.

It's triggered by a 3rd party package loader (work in progress), which does not support CGO, so the cgo tag is undefined.

But cross-compiling, maybe?

Do you need a exact reproduction case/steps?

I think it's better.

/cc @zombiezen

Cannot reproduce using CGO_ENABLED=0. For example

$ CGO_ENABLED=0 go build -x -a os/user
...
mkdir -p $WORK/os/user/_obj/
mkdir -p $WORK/os/
cd /home/jnml/go/src/os/user
/home/jnml/go/pkg/tool/linux_amd64/compile -o $WORK/os/user.a -trimpath $WORK
-p os/user -complete -buildid 5ea22e2e3f690c420c76db9f6b3a981a0173d286
-D _/home/jnml/go/src/os/user -I $WORK -pack ./lookup.go ./lookup_stubs.go ./user.go
$

I don't know why the build does not include getgrouplist_unix.go and listgroups_unix.go. unix is not an item in syslist, the suffix _unix should not exclude the file from build on linux and the build directive seems to be satisfied:

// +build dragonfly darwin freebsd !android,linux netbsd openbsd

Particulary, !androind and linux should be true in my case and thus the whole expression as well. I must be missing something. I'm no more sure if there really is a bug.

My env

$ go env
GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/jnml"
GORACE=""
GOROOT="/home/jnml/go"
GOTOOLDIR="/home/jnml/go/pkg/tool/linux_amd64"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build543108208=/tmp/go-build -gno-record-gcc-switches"
CXX="g++"
CGO_ENABLED="1"
$ 

Normally if cgo is enabled then files with import "C" are built, and if cgo is not enabled then files with import "C" are ignored. Search for isCgo in go/build/build.go.

I don't know what the problem is here, but it would help to know how to reproduce it.

Thanks for clarifying. It means the bug is not in the Go project. Sorry for the noise.