cmd/go: 1.8beta2 cross compilation fails without CGO_ENABLED=0

[tsuna]

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

go version go1.8beta2 darwin/amd64

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

mid-2012 MBP running macOS 10.9.5

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/tsuna/go"
GORACE=""
GOROOT="/usr/local/Cellar/go/1.8beta2/libexec"
GOTOOLDIR="/usr/local/Cellar/go/1.8beta2/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"
PKG_CONFIG="pkg-config"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"

What did you do?

Try to cross-compile the following program

package main

import "net"

func main() {
	net.Listen("tcp", "127.0.0.1:0")
}

What did you expect to see?

$ brew switch go 1.7.4
3 links created for /usr/local/Cellar/go/1.7.4
$ GOOS=linux GOARCH=386 go build ./main.go
$ file main
main: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), statically linked, not stripped

What did you see instead?

$ brew switch go 1.8beta2
3 links created for /usr/local/Cellar/go/1.8beta2
$ GOOS=linux GOARCH=386 go build ./main.go
# runtime/cgo
ld: unknown option: --build-id=none
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Additional information

Output with -x with Go 1.7.4:

$ GOOS=linux GOARCH=386 go build -x ./main.go
WORK=/var/folders/8j/3m62t7m92958kqxt9s3chtrr0000gn/T/go-build342276376
mkdir -p $WORK/command-line-arguments/_obj/
mkdir -p $WORK/command-line-arguments/_obj/exe/
cd /Users/tsuna/go/src/arista
/usr/local/Cellar/go/1.7.4/libexec/pkg/tool/darwin_amd64/compile -o $WORK/command-line-arguments.a -trimpath $WORK -p main -complete -buildid fe4cb02508eb842193f386e2b4cc9600cbc8577a -D _/Users/tsuna/go/src/arista -I $WORK -pack ./main.go
cd .
/usr/local/Cellar/go/1.7.4/libexec/pkg/tool/darwin_amd64/link -o $WORK/command-line-arguments/_obj/exe/a.out -L $WORK -extld=clang -buildmode=exe -buildid=fe4cb02508eb842193f386e2b4cc9600cbc8577a $WORK/command-line-arguments.a
mv $WORK/command-line-arguments/_obj/exe/a.out main

Output with -x with Go 1.8beta2:

$ GOOS=linux GOARCH=386 go build -x ./main.go
WORK=/var/folders/8j/3m62t7m92958kqxt9s3chtrr0000gn/T/go-build080300991
mkdir -p $WORK/runtime/cgo/_obj/
mkdir -p $WORK/runtime/
cd /usr/local/Cellar/go/1.8beta2/libexec/src/runtime/cgo
CGO_LDFLAGS="-g" "-O2" "-lpthread" /usr/local/Cellar/go/1.8beta2/libexec/pkg/tool/darwin_amd64/cgo -objdir $WORK/runtime/cgo/_obj/ -importpath runtime/cgo -import_runtime_cgo=false -import_syscall=false -- -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror cgo.go
cd $WORK
clang -fdebug-prefix-map=a=b -c trivial.c
clang -gno-record-gcc-switches -c trivial.c
cd /usr/local/Cellar/go/1.8beta2/libexec/src/runtime/cgo
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/_cgo_export.o -c $WORK/runtime/cgo/_obj/_cgo_export.c
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/cgo.cgo2.o -c $WORK/runtime/cgo/_obj/cgo.cgo2.c
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_context.o -c ./gcc_context.c
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_fatalf.o -c ./gcc_fatalf.c
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_libinit.o -c ./gcc_libinit.c
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_linux_386.o -c ./gcc_linux_386.c
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_setenv.o -c ./gcc_setenv.c
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_traceback.o -c ./gcc_traceback.c
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_util.o -c ./gcc_util.c
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_386.o -c ./gcc_386.S
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/_cgo_main.o -c $WORK/runtime/cgo/_obj/_cgo_main.c
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -o $WORK/runtime/cgo/_obj/_cgo_.o $WORK/runtime/cgo/_obj/_cgo_main.o $WORK/runtime/cgo/_obj/_cgo_export.o $WORK/runtime/cgo/_obj/cgo.cgo2.o $WORK/runtime/cgo/_obj/gcc_context.o $WORK/runtime/cgo/_obj/gcc_fatalf.o $WORK/runtime/cgo/_obj/gcc_libinit.o $WORK/runtime/cgo/_obj/gcc_linux_386.o $WORK/runtime/cgo/_obj/gcc_setenv.o $WORK/runtime/cgo/_obj/gcc_traceback.o $WORK/runtime/cgo/_obj/gcc_util.o $WORK/runtime/cgo/_obj/gcc_386.o -g -O2 -lpthread
/usr/local/Cellar/go/1.8beta2/libexec/pkg/tool/darwin_amd64/cgo -dynpackage cgo -dynimport $WORK/runtime/cgo/_obj/_cgo_.o -dynout $WORK/runtime/cgo/_obj/_cgo_import.go -dynlinker
cd $WORK
clang -no-pie -c trivial.c
cd /usr/local/Cellar/go/1.8beta2/libexec/src/runtime/cgo
clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -o $WORK/runtime/cgo/_obj/_all.o $WORK/runtime/cgo/_obj/_cgo_export.o $WORK/runtime/cgo/_obj/cgo.cgo2.o $WORK/runtime/cgo/_obj/gcc_context.o $WORK/runtime/cgo/_obj/gcc_fatalf.o $WORK/runtime/cgo/_obj/gcc_libinit.o $WORK/runtime/cgo/_obj/gcc_linux_386.o $WORK/runtime/cgo/_obj/gcc_setenv.o $WORK/runtime/cgo/_obj/gcc_traceback.o $WORK/runtime/cgo/_obj/gcc_util.o $WORK/runtime/cgo/_obj/gcc_386.o -g -O2 -Wl,-r -nostdlib -Wl,--build-id=none
# runtime/cgo
ld: unknown option: --build-id=none
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Output with -x with Go 1.8beta2 with CGO_ENABLED=0:

$ CGO_ENABLED=0 GOOS=linux GOARCH=386 go build -x ./main.go
WORK=/var/folders/8j/3m62t7m92958kqxt9s3chtrr0000gn/T/go-build902542865
mkdir -p $WORK/net/_obj/
mkdir -p $WORK/
cd /usr/local/Cellar/go/1.8beta2/libexec/src/net
/usr/local/Cellar/go/1.8beta2/libexec/pkg/tool/darwin_amd64/compile -o $WORK/net.a -trimpath $WORK -p net -buildid faa57ce85e83a4bd8e6d6a838952d59be1a0d72c -D _/usr/local/Cellar/go/1.8beta2/libexec/src/net -I $WORK -pack ./addrselect.go ./cgo_stub.go ./conf.go ./dial.go ./dnsclient.go ./dnsclient_unix.go ./dnsconfig_unix.go ./dnsmsg.go ./fd_mutex.go ./fd_poll_runtime.go ./fd_posix.go ./fd_unix.go ./file.go ./file_unix.go ./hook.go ./hook_cloexec.go ./hook_unix.go ./hosts.go ./interface.go ./interface_linux.go ./ip.go ./iprawsock.go ./iprawsock_posix.go ./ipsock.go ./ipsock_posix.go ./lookup.go ./lookup_unix.go ./mac.go ./net.go ./nss.go ./parse.go ./pipe.go ./port.go ./port_unix.go ./sendfile_linux.go ./sock_cloexec.go ./sock_linux.go ./sock_posix.go ./sockopt_linux.go ./sockopt_posix.go ./sockoptip_linux.go ./sockoptip_posix.go ./tcpsock.go ./tcpsock_posix.go ./tcpsockopt_posix.go ./tcpsockopt_unix.go ./udpsock.go ./udpsock_posix.go ./unixsock.go ./unixsock_posix.go ./writev_unix.go
mkdir -p $WORK/command-line-arguments/_obj/
mkdir -p $WORK/command-line-arguments/_obj/exe/
cd /Users/tsuna/go/src/arista
/usr/local/Cellar/go/1.8beta2/libexec/pkg/tool/darwin_amd64/compile -o $WORK/command-line-arguments.a -trimpath $WORK -p main -complete -buildid 75b54d4cf228f82475f968e679ea5b98632c9f49 -D _/Users/tsuna/go/src/arista -I $WORK -pack ./main.go
cd .
/usr/local/Cellar/go/1.8beta2/libexec/pkg/tool/darwin_amd64/link -o $WORK/command-line-arguments/_obj/exe/a.out -L $WORK -extld=clang -buildmode=exe -buildid=75b54d4cf228f82475f968e679ea5b98632c9f49 $WORK/command-line-arguments.a
mv $WORK/command-line-arguments/_obj/exe/a.out main

[davecheney]

This is a bug in homebrew, they homebrew recipe author hard codes cgo to 1 at all times.

…

On Sat, 17 Dec 2016, 20:04 Benoit Sigoure ***@***.***> wrote: What version of Go are you using (go version)? go version go1.8beta2 darwin/amd64 What operating system and processor architecture are you using (go env)? mid-2012 MBP running macOS 10.9.5 GOARCH="amd64" GOBIN="" GOEXE="" GOHOSTARCH="amd64" GOHOSTOS="darwin" GOOS="darwin" GOPATH="/Users/tsuna/go" GORACE="" GOROOT="/usr/local/Cellar/go/1.8beta2/libexec" GOTOOLDIR="/usr/local/Cellar/go/1.8beta2/libexec/pkg/tool/darwin_amd64" GCCGO="gccgo" CC="clang" GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -fno-common" CXX="clang++" CGO_ENABLED="1" PKG_CONFIG="pkg-config" CGO_CFLAGS="-g -O2" CGO_CPPFLAGS="" CGO_CXXFLAGS="-g -O2" CGO_FFLAGS="-g -O2" CGO_LDFLAGS="-g -O2" What did you do? Try to cross-compile the following program package main import "net" func main() { net.Listen("tcp", "127.0.0.1:0") } What did you expect to see? $ brew switch go 1.7.4 3 links created for /usr/local/Cellar/go/1.7.4 $ GOOS=linux GOARCH=386 go build ./main.go $ file main main: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), statically linked, not stripped What did you see instead? $ brew switch go 1.8beta2 3 links created for /usr/local/Cellar/go/1.8beta2 $ GOOS=linux GOARCH=386 go build ./main.go # runtime/cgo ld: unknown option: --build-id=none clang: error: linker command failed with exit code 1 (use -v to see invocation) Additional information Output with -x with Go 1.7.4: $ GOOS=linux GOARCH=386 go build -x ./main.go WORK=/var/folders/8j/3m62t7m92958kqxt9s3chtrr0000gn/T/go-build342276376 mkdir -p $WORK/command-line-arguments/_obj/ mkdir -p $WORK/command-line-arguments/_obj/exe/ cd /Users/tsuna/go/src/arista /usr/local/Cellar/go/1.7.4/libexec/pkg/tool/darwin_amd64/compile -o $WORK/command-line-arguments.a -trimpath $WORK -p main -complete -buildid fe4cb02508eb842193f386e2b4cc9600cbc8577a -D _/Users/tsuna/go/src/arista -I $WORK -pack ./main.go cd . /usr/local/Cellar/go/1.7.4/libexec/pkg/tool/darwin_amd64/link -o $WORK/command-line-arguments/_obj/exe/a.out -L $WORK -extld=clang -buildmode=exe -buildid=fe4cb02508eb842193f386e2b4cc9600cbc8577a $WORK/command-line-arguments.a mv $WORK/command-line-arguments/_obj/exe/a.out main Output with -x with Go 1.8beta2: $ GOOS=linux GOARCH=386 go build -x ./main.go WORK=/var/folders/8j/3m62t7m92958kqxt9s3chtrr0000gn/T/go-build080300991 mkdir -p $WORK/runtime/cgo/_obj/ mkdir -p $WORK/runtime/ cd /usr/local/Cellar/go/1.8beta2/libexec/src/runtime/cgo CGO_LDFLAGS="-g" "-O2" "-lpthread" /usr/local/Cellar/go/1.8beta2/libexec/pkg/tool/darwin_amd64/cgo -objdir $WORK/runtime/cgo/_obj/ -importpath runtime/cgo -import_runtime_cgo=false -import_syscall=false -- -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror cgo.go cd $WORK clang -fdebug-prefix-map=a=b -c trivial.c clang -gno-record-gcc-switches -c trivial.c cd /usr/local/Cellar/go/1.8beta2/libexec/src/runtime/cgo clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/_cgo_export.o -c $WORK/runtime/cgo/_obj/_cgo_export.c clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/cgo.cgo2.o -c $WORK/runtime/cgo/_obj/cgo.cgo2.c clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_context.o -c ./gcc_context.c clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_fatalf.o -c ./gcc_fatalf.c clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_libinit.o -c ./gcc_libinit.c clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_linux_386.o -c ./gcc_linux_386.c clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_setenv.o -c ./gcc_setenv.c clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_traceback.o -c ./gcc_traceback.c clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_util.o -c ./gcc_util.c clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/gcc_386.o -c ./gcc_386.S clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -I $WORK/runtime/cgo/_obj/ -g -O2 -Wall -Werror -o $WORK/runtime/cgo/_obj/_cgo_main.o -c $WORK/runtime/cgo/_obj/_cgo_main.c clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -o $WORK/runtime/cgo/_obj/_cgo_.o $WORK/runtime/cgo/_obj/_cgo_main.o $WORK/runtime/cgo/_obj/_cgo_export.o $WORK/runtime/cgo/_obj/cgo.cgo2.o $WORK/runtime/cgo/_obj/gcc_context.o $WORK/runtime/cgo/_obj/gcc_fatalf.o $WORK/runtime/cgo/_obj/gcc_libinit.o $WORK/runtime/cgo/_obj/gcc_linux_386.o $WORK/runtime/cgo/_obj/gcc_setenv.o $WORK/runtime/cgo/_obj/gcc_traceback.o $WORK/runtime/cgo/_obj/gcc_util.o $WORK/runtime/cgo/_obj/gcc_386.o -g -O2 -lpthread /usr/local/Cellar/go/1.8beta2/libexec/pkg/tool/darwin_amd64/cgo -dynpackage cgo -dynimport $WORK/runtime/cgo/_obj/_cgo_.o -dynout $WORK/runtime/cgo/_obj/_cgo_import.go -dynlinker cd $WORK clang -no-pie -c trivial.c cd /usr/local/Cellar/go/1.8beta2/libexec/src/runtime/cgo clang -I . -fPIC -m32 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -o $WORK/runtime/cgo/_obj/_all.o $WORK/runtime/cgo/_obj/_cgo_export.o $WORK/runtime/cgo/_obj/cgo.cgo2.o $WORK/runtime/cgo/_obj/gcc_context.o $WORK/runtime/cgo/_obj/gcc_fatalf.o $WORK/runtime/cgo/_obj/gcc_libinit.o $WORK/runtime/cgo/_obj/gcc_linux_386.o $WORK/runtime/cgo/_obj/gcc_setenv.o $WORK/runtime/cgo/_obj/gcc_traceback.o $WORK/runtime/cgo/_obj/gcc_util.o $WORK/runtime/cgo/_obj/gcc_386.o -g -O2 -Wl,-r -nostdlib -Wl,--build-id=none # runtime/cgo ld: unknown option: --build-id=none clang: error: linker command failed with exit code 1 (use -v to see invocation) Output with -x with Go 1.8beta2 with CGO_ENABLED=0: $ CGO_ENABLED=0 GOOS=linux GOARCH=386 go build -x ./main.go WORK=/var/folders/8j/3m62t7m92958kqxt9s3chtrr0000gn/T/go-build902542865 mkdir -p $WORK/net/_obj/ mkdir -p $WORK/ cd /usr/local/Cellar/go/1.8beta2/libexec/src/net /usr/local/Cellar/go/1.8beta2/libexec/pkg/tool/darwin_amd64/compile -o $WORK/net.a -trimpath $WORK -p net -buildid faa57ce85e83a4bd8e6d6a838952d59be1a0d72c -D _/usr/local/Cellar/go/1.8beta2/libexec/src/net -I $WORK -pack ./addrselect.go ./cgo_stub.go ./conf.go ./dial.go ./dnsclient.go ./dnsclient_unix.go ./dnsconfig_unix.go ./dnsmsg.go ./fd_mutex.go ./fd_poll_runtime.go ./fd_posix.go ./fd_unix.go ./file.go ./file_unix.go ./hook.go ./hook_cloexec.go ./hook_unix.go ./hosts.go ./interface.go ./interface_linux.go ./ip.go ./iprawsock.go ./iprawsock_posix.go ./ipsock.go ./ipsock_posix.go ./lookup.go ./lookup_unix.go ./mac.go ./net.go ./nss.go ./parse.go ./pipe.go ./port.go ./port_unix.go ./sendfile_linux.go ./sock_cloexec.go ./sock_linux.go ./sock_posix.go ./sockopt_linux.go ./sockopt_posix.go ./sockoptip_linux.go ./sockoptip_posix.go ./tcpsock.go ./tcpsock_posix.go ./tcpsockopt_posix.go ./tcpsockopt_unix.go ./udpsock.go ./udpsock_posix.go ./unixsock.go ./unixsock_posix.go ./writev_unix.go mkdir -p $WORK/command-line-arguments/_obj/ mkdir -p $WORK/command-line-arguments/_obj/exe/ cd /Users/tsuna/go/src/arista /usr/local/Cellar/go/1.8beta2/libexec/pkg/tool/darwin_amd64/compile -o $WORK/command-line-arguments.a -trimpath $WORK -p main -complete -buildid 75b54d4cf228f82475f968e679ea5b98632c9f49 -D _/Users/tsuna/go/src/arista -I $WORK -pack ./main.go cd . /usr/local/Cellar/go/1.8beta2/libexec/pkg/tool/darwin_amd64/link -o $WORK/command-line-arguments/_obj/exe/a.out -L $WORK -extld=clang -buildmode=exe -buildid=75b54d4cf228f82475f968e679ea5b98632c9f49 $WORK/command-line-arguments.a mv $WORK/command-line-arguments/_obj/exe/a.out main — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#18360>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAAcAxwqvR2WZfmSRkP7B-oA6lxaks0iks5rI6WkgaJpZM4LP1tX> .

[tsuna]

This is my go env with 1.7.4:

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/tsuna/go"
GORACE=""
GOROOT="/usr/local/Cellar/go/1.7.4/libexec"
GOTOOLDIR="/usr/local/Cellar/go/1.7.4/libexec/pkg/tool/darwin_amd64"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"

Looking at this a bit closer, I see that the differences between 1.7.4 and 1.8beta2, I'm wondering whether this is not a packaging bug with homebrew, as it appears that now the default value of CGO_ENABLED is recorded when go itself is built (by cmd/dist/buildgo.go), and on my system I found

$ rg defaultCGO_ENABLED /usr/local/Cellar/go/1.8beta2
[...]
/usr/local/Cellar/go/1.8beta2/libexec/src/go/build/zcgo.go
5:const defaultCGO_ENABLED = "1"

This was changed in commit 0ba3c60 as part of #12808, which I just read. I'm not sure what to think, with either of these versions of Go go env shows CGO_ENABLED="1" but with Go 1.7.4 it gets turned off automatically when cross compiling, which seems to be what we want based on #5104.

[tsuna]

Ha, just seeing your reply @davecheney, looks like we're coming to the same conclusion. So was this working by chance with homebrew with earlier versions of Go, because CGO_ENABLED wasn't sticky before?

Are we really saying "if you want to cross-compile, you should build Go itself with CGO_ENABLED=0 or, at the time you cross-compile, build with CGO_ENABLED=0"?

[davecheney]

Nope. The go tool does the right thing, cgo is disabled when the host and target do not match. The current suspicion is homebrew have altered this behaviour.

…

On Sat, 17 Dec 2016, 20:14 Benoit Sigoure ***@***.***> wrote: Ha, just seeing your reply @davecheney <https://github.com/davecheney>, looks like we're coming to the same conclusion. So was this working by chance with homebrew with earlier versions of Go, because CGO_ENABLED wasn't sticky before? Are we really saying "if you want to cross-compile, you should build Go itself with CGO_ENABLED=0 *or*, at the time you cross-compile, build with CGO_ENABLED=0"? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#18360 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAAcA2f-T8nbeQ8TLjxl7YrKaipFR-CIks5rI6f0gaJpZM4LP1tX> .

[tsuna]

I'm not sure I follow now... But homebrew didn't change how it builds Go between 1.7.4 and 1.8beta2. See https://github.com/Homebrew/homebrew-core/commits/master/Formula/go.rb – the formula has been building Go with CGO_ENABLED=1 in the environment by default for a long time.

[minux]

I think the Homebrew maintainers confused about when it's necessary to set CGO_ENABLED: It's almost never necessary to set CGO_ENABLED when doing native compile. (You only need to set CGO_ENABLED=0 when doing a native compile when you have working C compiler but do NOT want to use cgo.) Just don't set CGO_ENABLED, and Go should do the correct thing. CGO_ENABLED is indeed made sticky in this release to fix #12808.

[tsuna]

OK so their formula was working by chance before. What you're saying is that unless the user wants to explicitly disable cgo by building the formula with --without-cgo, the formula should not set CGO_ENABLED to any value during the build.

I tested this change to their formula and indeed things now works as intended:

--- a/Formula/go.rb
+++ b/Formula/go.rb
@@ -63,7 +63,9 @@ class Go < Formula
     cd "src" do
       ENV["GOROOT_FINAL"] = libexec
       ENV["GOOS"]         = "darwin"
-      ENV["CGO_ENABLED"]  = build.with?("cgo") ? "1" : "0"
+      if build.without? "cgo"
+        ENV["CGO_ENABLED"] = "0"
+      end
       system "./make.bash", "--no-clean"
     end
 

I'll send them a pull request. Thanks for the quick response!