doc: document race detector cgo requirements

[andig]

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

$ go version
go version go1.17.6 darwin/arm64

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="arm64"
GOBIN=""
GOCACHE="/Users/andig/Library/Caches/go-build"
GOENV="/Users/andig/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="arm64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/andig/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/andig/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/opt/homebrew/Cellar/go/1.17.6/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/opt/homebrew/Cellar/go/1.17.6/libexec/pkg/tool/darwin_arm64"
GOVCS=""
GOVERSION="go1.17.6"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/dev/null"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/sv/rs_453y57xj86xsbz3kw1mbc0000gn/T/go-build3031970245=/tmp/go-build -gno-record-gcc-switches -fno-common"
GOROOT/bin/go version: go version go1.17.6 darwin/arm64
GOROOT/bin/go tool compile -V: compile version go1.17.6
uname -v: Darwin Kernel Version 21.3.0: Wed Jan  5 21:37:58 PST 2022; root:xnu-8019.80.24~20/RELEASE_ARM64_T8101
ProductName:	macOS
ProductVersion:	12.2
BuildVersion:	21D49
lldb --version: lldb-1300.0.42.3
Swift version 5.5.2-dev

What did you do?

Use goreleaser to create multi-platform release. Amongst others, goreleaser executes:

CGO_ENABLED=0 GOOS=windows GOARCH=amd64 go build -race  main.go

What did you expect to see?

Sucess

What did you see instead?

go build: -race requires cgo

I would like to request documenting the cgo requirements per platform as part of https://go.dev/doc/articles/race_detector.

[mengzhuo]

@ianlancetaylor How about this doc?

Requirements

The race detector require cgo and support the os/arch below:

• linux/amd64
• linux/ppc64le
• linux/arm64
• freebsd/amd64
• netbsd/amd64
• darwin/amd64
• darwin/arm64
• windows/amd64

[ALTree]

@ianlancetaylor How about this doc?

Requirements

The race detector require cgo and support the os/arch below:

* linux/amd64

* linux/ppc64le

* linux/arm64

* freebsd/amd64

* netbsd/amd64

* darwin/amd64

* darwin/arm64

* windows/amd64

I would keep the list inline, also "s" missing on the verb, my proposal:

The race detector requires cgo to be enabled, and supports linux/amd64, linux/ppc64le, linux/arm64, freebsd/amd64, netbsd/amd64, darwin/amd64, darwin/arm64, and windows/amd64.

[andig]

Thank you @ALTree I was under the impression that it didn't need cgo on all platforms, but if it's helpful to mention that it does!

[ALTree]

@andig I think #6508 and #9918 still apply.

[gopherbot]

Change https://go.dev/cl/386454 mentions this issue: _content: cgo requirement for race detector

[inliquid]

Could anyone please explain why this was working perfectly on Windows with go1.19, and suddenly started to complain about CGO in go1.20? What's changed which made it effectively malfunct on Windows?