Please answer these questions before submitting your issue. Thanks!

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

go version devel +bcf2d74 Tue May 9 16:37:59 2017 +0800 linux/amd64

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

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/weixia01/workspace/golang/gopath"
GORACE=""
GOROOT="/home/weixia01/workspace/golang/internal"
GOTOOLDIR="/home/weixia01/workspace/golang/internal/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build959788086=/tmp/go-build -gno-record-gcc-switches"
CXX="g++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"

What did you do?

$ go tool compile internal/test/helloworld.go
$ go tool objdump helloworld.o

What did you expect to see?

objdump run successfully

What did you see instead?

objdump: open helloworld.o: unrecognized object file