x/mobile: 'gomobile bind -x' fails due to unused '-mno-thumb' argument passed to clang

[ssrlxl]

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

$ go version
go version go1.12 darwin/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
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/shaoshengrong/Library/Caches/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/shaoshengrong/code/go/"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/go"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
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 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/kc/cg92l_vj04n2h70mw6clq22w0000gn/T/go-buil

What did you do?

exec : gomobile bind -x
error: clang: error: argument unused during compilation: '-mno-thumb' [-Werror,-Wunused-command-line-argument]

What did you expect to see?

exec : gomobile bind -x
error: clang: error: argument unused during compilation: '-mno-thumb' [-Werror,-Wunused-command-line-argument]

What did you see instead?

exec : gomobile bind -x
error: clang: error: argument unused during compilation: '-mno-thumb' [-Werror,-Wunused-command-line-argument]

[bcmills]

Possibly related to #30415?

[bcmills]

CC @eliasnaur @hyangah

[eliasnaur]

I can't reproduce this on my macOS 10.14.1. Do you have NDK version r19b installed as well as run go get -u golang.org/x/mobile/cmd/...?