cmd/build: debug and test fail to run on mac OS 10.15.4

[timwangmusic]

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

$ go version go1.14.2 darwin/amd64

Does this issue reproduce with the latest release?

Tested with Go 1.14.2

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

go env Output

$ go env
GO111MODULE=""

GOARCH="amd64"

GOBIN=""

GOCACHE="/Users/Weihe/Library/Caches/go-build"

GOENV="/Users/Weihe/Library/Application Support/go/env"

GOEXE=""

GOFLAGS=""

GOHOSTARCH="amd64"

GOHOSTOS="darwin"

GOINSECURE=""

GONOPROXY=""

GONOSUMDB=""

GOOS="darwin"

GOPATH="/Users/Weihe/go"

GOPRIVATE=""

GOPROXY="https://proxy.golang.org,direct"

GOROOT="/usr/local/Cellar/go/1.14.2_1/libexec"

GOSUMDB="sum.golang.org"

GOTMPDIR=""

GOTOOLDIR="/usr/local/Cellar/go/1.14.2_1/libexec/pkg/tool/darwin_amd64"

GCCGO="gccgo"

AR="ar"

CC="clang"

CXX="clang++"

CGO_ENABLED="1"

GOMOD="/Users/Weihe/code/Mew/go.mod"

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/h6/znnjnf1n2t970n6rdht824t40000gn/T/go-build615583220=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

tried to run test suite on a golang code repo with command go test ./....
debug mode for main application also fails.

What did you expect to see?

Expect test case to run.

What did you see instead?

GOROOT=/usr/local/Cellar/go/1.14.2_1/libexec #gosetup
GOPATH=/Users/Weihe/go #gosetup
/usr/local/Cellar/go/1.14.2_1/libexec/bin/go build -o /private/var/folders/h6/znnjnf1n2t970n6rdht824t40000gn/T/___go_build_mew_go -gcflags "all=-N -l" /Users/Weihe/code/Mew/mew.go #gosetup
`# runtime/cgo`
In file included from gcc_darwin_amd64.c:6:
/usr/local/include/pthread.h:331:6: error: macro expansion producing 'defined' has undefined behavior [-Werror,-Wexpansion-to-defined]
/usr/local/include/pthread.h:200:2: note: expanded from macro '_PTHREAD_SWIFT_IMPORTER_NULLABILITY_COMPAT'
/usr/local/include/pthread.h:331:6: error: macro expansion producing 'defined' has undefined behavior [-Werror,-Wexpansion-to-defined]
/usr/local/include/pthread.h:200:34: note: expanded from macro '_PTHREAD_SWIFT_IMPORTER_NULLABILITY_COMPAT'
/usr/local/include/pthread.h:540:6: error: macro expansion producing 'defined' has undefined behavior [-Werror,-Wexpansion-to-defined]
/usr/local/include/pthread.h:200:2: note: expanded from macro '_PTHREAD_SWIFT_IMPORTER_NULLABILITY_COMPAT'
/usr/local/include/pthread.h:540:6: error: macro expansion producing 'defined' has undefined behavior [-Werror,-Wexpansion-to-defined]
/usr/local/include/pthread.h:200:34: note: expanded from macro '_PTHREAD_SWIFT_IMPORTER_NULLABILITY_COMPAT'

[andybons]

Can you provide a minimal code example that shows this error?

Thanks

[ALTree]

The OP in #38876 reported this error and provided a reproducer. Closing here in favour of the other thread.