Error "build constraints exclude all Go files" when GOARCH=386 with import "C"

[Bassem-Ramzy]

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

$ go version
go version go1.16.2 windows/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
set GO111MODULE=
set GOARCH=386
set GOBIN=
set GOCACHE=C:\Users\basse\AppData\Local\go-build
set GOENV=C:\Users\basse\AppData\Roaming\go\env
set GOEXE=.exe
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMODCACHE=C:\Users\basse\go\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=C:\Users\basse\go;C:\Users\basse\source\repos\xhptdc8_babel\go\info\src-cgo;
set GOPRIVATE=
set GOPROXY=https://proxy.golang.org,direct
set GOROOT=C:\Program Files\Go
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLDIR=C:\Program Files\Go\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=go1.16.2
set GCCGO=gccgo
set GO386=sse2
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=0
set GOMOD=C:\Users\basse\source\repos\xhptdc8_babel\go\info\hello\go.mod
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m32 -fmessage-length=0 -fdebug-prefix-map=C:\Users\basse\AppData\Local\Temp\go-build4135007010=/tmp/go-build -gno-record-gcc-switches

What did you do?

I'm using CGO package to import C code, and I want to build an x86 (386) windows version of it. I found out this should be done by setting GOARCH=386.
While it builds properly on my default environment settings (GOARCH=amd64), when I set the environment variable to "386", I get error: build constraints exclude all Go files in my file.

// hello.go
package main

/*
int CFunc() {
}
*/
import "C"

import (
	"fmt"
)

func main() {
	fmt.Println("Hello, Go!")
}

go.mod

module hello

go 1.16

I do

go build

Trials:

• Without import "C", I get no error.
• With // +build windows,386 or // +build windows,386,!cgo before package main I still get the same error

What did you expect to see?

No Error

What did you see instead?

C:\Users\basse\source\repos\xhptdc8_babel\go\info\hello>go build
package hello: build constraints exclude all Go files in C:\Users\basse\source\repos\xhptdc8_babel\go\info\hello

[Bassem-Ramzy]

Setting

set CGO_ENABLED=1  

Generates another type of errors:

F:/Work/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: skipping incompatible F:/Work/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32/lib/libmingwthrd.a when searching for -lmingwthrd
F:/Work/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: skipping incompatible F:/Work/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32/lib\libmingwthrd.a when searching for -lmingwthrd
F:/Work/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: skipping incompatible F:/Work/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32/lib/libmingwthrd.a when searching for -lmingwthrd
F:/Work/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: cannot find -lmingwthrd
.
.
.

[seankhliao]

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