cmd/go: unhelpful error when cross-compiling for windows with cgo

[josharian]

package main

import "fmt"
import "C"

func main() {
	fmt.Printf("main=%p\n", main)
}

$ go build .
$ GOOS=windows go build .
can't load package: package .: no buildable Go source files in /Users/josh/go/tip/w

If you remove the import "C":

$ go build .
$ GOOS=windows go build .

If (like me) you didn't notice the import "C", this is a pretty puzzling error message.

[odeke-em]

Am using OSX(darwin): same error when building for linux

$ GOOS=linux go build .
can't load package: package .: no buildable Go source files in /Users/emmanuelodeke/Desktop/openSrc/bugs/golang/20199

but when building for the same OS as the host OS, no error

$ GOOS=darwin go build . && echo successful
successful

[odeke-em]

Update: one can reproduce the problem on the host OS == final OS if I set CGO_ENABLED=0 which might not make much sense since using import "C" but here is the error

$ GOOS=darwin CGO_ENABLED=0 go build . && echo successful
can't load package: package .: no buildable Go source files in /Users/emmanuelodeke/Desktop/openSrc/bugs/golang/20199

on Go version

$ go version
go version devel +643be70 Wed May 10 19:30:42 2017 +0000 darwin/amd64

[bcmills]

Dup of #24068?

[gopherbot]

Timed out in state WaitingForInfo. Closing.

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