Invalid gopkg.in package and rev in
Question: When attempting to build with Pants, I am seeing the following error:

    
    
      File "build/bdist.macosx-10.10-intel/egg/pants/contrib/go/tasks/go_fetch.py", line 154, in _transitive_download_remote_libs
        all_known_addresses)
      File "build/bdist.macosx-10.10-intel/egg/pants/contrib/go/tasks/go_fetch.py", line 105, in _transitive_download_remote_libs
        fetcher.fetch(go_remote_lib.import_path, dest=tmp_fetch_root, rev=go_remote_lib.rev)
      File "build/bdist.macosx-10.10-intel/egg/pants/contrib/go/subsystems/fetchers.py", line 437, in fetch
        github_root, github_rev = self._map_import_path(import_path, rev)
      File "/Users/chad/.cache/pants/setup/bootstrap/pants.mbFDa8/install/lib/python2.7/site-packages/pants/util/memo.py", line 95, in memoize
        result = func(*args, **kwargs)
      File "build/bdist.macosx-10.10-intel/egg/pants/contrib/go/subsystems/fetchers.py", line 454, in _map_import_path
        raise self.FetchError('Invalid gopkg.in package and rev in: {}'.format(import_path))
    
    Exception message: Invalid gopkg.in package and rev in: gopkg.in/amz.v1/aws
    

Here is the contents of my BUILD file:

    
    
    # Auto-generated by pants!
    # To re-generate run: `pants buildgen.go --materialize --remote`
    
    go_remote_library(rev='v1')
    

Looking into the code, I see that the error comes from a failure to match a
regex in fetchers.py, [on line
453](https://github.com/pantsbuild/pants/blob/ed5badda3d518c869aa22d6401f604aa864fcfc4/contrib/go/src/python/pants/contrib/go/subsystems/fetchers.py#L453).

I am running Pants version 0.0.59 on Mac OS X 10.10 (Yosemite)


Answer: Noting that [@Huckphin](http://stackoverflow.com/users/38009/huckphin)
stumbled on a bug here in `pantsbuild.pants<=0.0.59`. He filed an
[issue](https://github.com/pantsbuild/pants/issues/2581) and now things are
fixed up for handling `gopkg.in` remote import paths that point to sub-
packages in the remote repo. The fix will be released with the regular Friday
release on 11/20/2015 in `0.0.60`.

