context.GOOS:   true,
		context.GOARCH: true,
	}
	if context.CgoEnabled {
		ctags["cgo"] = true
	}
	for _, tag := range context.BuildTags {
		ctags[tag] = true
	}
	// TODO: ReleaseTags (need to load default)
	key := dir

	// explicit on GOOS and GOARCH as global cache will use "all" cached packages for
	// an indirect imported package. See https://github.com/golang/go/issues/21181