状況
GAE/GoのProjectにglideを採用した後にginを追加した時
原因
ginと他libraryのprotobufのバージョンが違うから（恐らくginの依存管理で別のバージョンが打たれている）、
以下のようなログが出る。
[ERROR] This error means the referenced package was not found.
[ERROR] Missing file or directory errors usually occur when multiple packages
[ERROR] share a common dependency and the first reference encountered by the scanner
[ERROR] sets the version to one that does not contain a subpackage needed required
[ERROR] by another package that uses the shared dependency. Try setting a
[ERROR] version in your glide.yaml that works for all packages that share this
[ERROR] dependency.
対処
とりあえず、最新のコミットIDをversionに記載する感じで・・