Depending on rsc/letsencrypt breaks godep because godep doesn't support subvendoring and/or vendoring code that isn't checked into version control. The author is unwilling to fix this and this is breaking distribution by extension. rsc/letsencrypt#12 We have to hack our dependencies because we use godep and vendor distribution. It looks like this is a tiny project with only one file. Please rewrite and/or fork this dependency so that godep can be used to depend on distribution.