{"(gc", false, fmt.Errorf("parsing //go:build line: missing )")},
	{"gc gc", false, fmt.Errorf("parsing //go:build line: unexpected tag")},
	{"(gc))", false, fmt.Errorf("parsing //go:build line: unexpected )")},
}

func TestBuildParser(t *testing.T) {
	for _, tt := range buildParserTests {
		matched, err := matchexpr(tt.x)
		if matched != tt.matched || !reflect.DeepEqual(err, tt.err) {