I noticed this while attempting to build rclone with go1.8beta and mips

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

go version devel +41908a5 Thu Dec 1 02:54:21 2016 +0000 linux/amd64

I'm using ca83bd2 of the x/sys repo (2 December 2016)

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

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/ncw/go"
GORACE=""
GOROOT="/opt/go/go1.8"
GOTOOLDIR="/opt/go/go1.8/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build407009917=/tmp/go-build -gno-record-gcc-switches"
CXX="g++"
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?

$ GOARCH=mips GOOS=linux go install golang.org/x/sys/unix/
# golang.org/x/sys/unix
../../../golang.org/x/sys/unix/flock.go:18: undefined: Flock_t
../../../golang.org/x/sys/unix/sockcmsg_linux.go:14: undefined: Ucred
../../../golang.org/x/sys/unix/sockcmsg_linux.go:27: undefined: Ucred
../../../golang.org/x/sys/unix/sockcmsg_unix.go:42: undefined: Cmsghdr

Same for mipsle

What did you expect to see?

It to compile

What did you see instead?

Error messages about undefined symbols