Race detector should not require cgo

[rittneje]

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

$ go version
go version go1.13.10 linux/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
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/tmp/.gocache"
GOENV="/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH=""
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="0"
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 -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build323659760=/tmp/go-build -gno-record-gcc-switches"

What did you do?

CGO_ENABLED=0 go install -race <cmd>

What did you expect to see?

I expected it to create an executable without cgo that has race detection instrumentation.

We want to be able to run the resulting executable inside a FROM scratch docker container, so any dynamic linking against C libraries is not acceptable.

What did you see instead?

go install: -race requires cgo; enable cgo by setting CGO_ENABLED=1

If I turn on cgo, I can see there are some dynamically linked libraries, so the executable is not usable.

linux-vdso.so.1 (0x00007ffd8db6e000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fcf44b3e000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fcf4474d000)
/lib64/ld-linux-x86-64.so.2 (0x00007fcf44d5d000)

[randall77]

Dup of #9918 and #6508 .