"Go needs a system C compiler for use with cgo.\n"+
			"To set a C compiler, set CC=the-compiler.\n"+
			"To disable cgo, set CGO_ENABLED=0.\n%s%s", cc, err, outputHdr, output)
	}
}

func defaulttarg() string {
	// xgetwd might return a path with symlinks fully resolved, and if
	// there happens to be symlinks in goroot, then the hasprefix test
	// will never succeed. Instead, we use xrealwd to get a canonical