On Sat, Oct 11, 2014 at 04:23:37PM -0000, Jason R. Coombs wrote [1]:
> I suggest implementing the functionality as a separate method with a
> docstring explaining the purpose.

so that's what we have here. The docstring is adapted from the
cbd4f603 (egg_info: Search egg-base for files to add to the manifest,
2014-10-16) commit message.

It's a lot of docs for a single command (although there is a newsted
list comprehension), so I'm fine if you drop this commit before
merging. The motivation behind the lines would still be available in
the version control history:

  $ hg blame -c setuptools/command/egg_info.py | grep -A1 ei_cmd.egg_base
  cbd4f6038604: if ei_cmd.egg_base != os.curdir:
  cbd4f6038604: self.filelist.allfiles.extend([
  cbd4f6038604: os.path.join(ei_cmd.egg_base, path)
  cbd4f6038604: for path in distutils.filelist.findall(ei_cmd.egg_base)])
  80108b046cb6: self.filelist.include_pattern("*", prefix=ei_cmd.egg_info)
  $ hg log -vr cbd4f6038604
  changeset: 3163:cbd4f6038604
  ...
  description:
  egg_info: Search egg-base for files to add to the manifest
  Before this commit, this:

    $ mkdir -p /tmp/xyz/{home,lib,scripts,data,egg}
    $ cat >/tmp/xyz/home/.pydistutils.cfg <<EOF
  ...

[1]: https://bitbucket.org/pypa/setuptools/pull-request/85/egg_info-search-egg-base-for-files-to-add/diff#comment-3418032

Before this commit, this:

  $ mkdir -p /tmp/xyz/{home,lib,scripts,data,egg}
  $ cat >/tmp/xyz/home/.pydistutils.cfg <<EOF
  > [egg_info]
  > egg-base = /tmp/xyz/egg
  > EOF
  $ export PYTHONPATH=/tmp/xyz/lib
  $ export HOME=/tmp/xyz/home
  $ setup.py install --home=/tmp/xyz/home --install-lib=/tmp/xyz/lib \
  >   --install-scripts=/tmp/xyz/scripts --install-data=/tmp/xyz/data

drops a lot of metadata, installing only SOURCES.txt and zip-safe
under EGG-INFO.  The problem is that the metadata files are written to
egg-base, but egg-base is not searched when creating the manifest
because it's outside of the current directory.  Work around this by
explicitly searching egg-base with distutils.filelist.findall (which
is really the version monkeypatched in by setuptools/__init__.py).

Since findall records relative paths, prefix the returned paths with
egg-base, so the include_pattern looking for the absolute
ei_cmd.egg_info will match them.