Ah, thanks. You might also need to go get code.google.com/p/go.net/websocket if you haven't already.
import (
"go/build"
"path/filepath"
)
pkgInfo, err := build.Import("github.com/minikomi/pipesock", "", 0)
if err != nil {
panic(err)
}
webDirPath := filepath.Join(pkgInfo.Dir, "default")