ImportError：在GCE / Golang上没有名为appengine.tools的模块

Question

goapp deploy

总是得到

Traceback (most recent call last): File "/Users/{Username}/.go_appengine/google-cloud-sdk/platform/google_appengine/goapp", line 13, in <module> from google.appengine.tools import goroots ImportError: No module named appengine.tools

我该怎么办？