language/go/package.go
func (pkg *goPackage) isBuildable(c *config.Config) bool {
	return pkg.firstGoFile() != "" || !pkg.proto.sources.isEmpty()
}
func (pkg *goPackage) isBuildable(c *config.Config) bool {
	return pkg.firstGoFile() != "" || !pkg.proto.sources.isEmpty()
}
// isBuildable returns true if anything in the package is buildable.
// This is true if the package has Go code that satisfies build constraints
// on any platform or has proto files not in legacy mode.