update git log note in release doc

docs/source/development/release.txt

@@ -1,45 +1,53
 .. _releasing_ipython:
 
 =================
 Releasing IPython
 =================
 
 This section contains notes about the process that is used to release IPython.
 Our release process is currently not very formal and could be improved.
 
 Most of the release process is automated by the :file:`release` script in the
 :file:`tools` directory.  This is just a handy reminder for the release manager.
 
 #. For writing release notes, this will cleanly show who contributed as author
    of commits (get the previous release name from the tag list with ``git
    tag``)::
 
-   git log --pretty=format:"* %an" PREV_RELEASE... | sort | uniq
+        git log --format="* %aN" $PREV_RELEASE... | sort -u
+
+   .. note::
+
+        use::
+
+            git log --format="%aN <%aE>" $PREV_RELEASE... | sort -u -f
+        
+        To find duplicates and update :file:`.mailmap`
 
 #. Run :file:`build_release`, which does all the file checking and building
    that the real release script will do.  This will let you do test
    installations, check that the build procedure runs OK, etc.  You may want to
    disable a few things like multi-version RPM building while testing, because
    otherwise the build takes really long.
 
 #. Run the release script, which makes the tar.gz, eggs and Win32 .exe
    installer.  It posts them to the site and registers the release with PyPI.
 
 #. Update the website with announcements and links to the updated changes.txt
    in html form. Remember to put a short note on the news page of the site.
    
 #. Drafting a short release announcement with i) highlights and ii) a link to
    the html version of the :ref:`Whats new <whatsnew_index>` section of the 
    documentation.
 
 #. Make sure that the released version of the docs is live on the site.  For
    this we are now using the gh-pages system:
 
    - Make a static directory for the final copy of the release docs.
    - Update the :file:`index.rst` file and run :file:`build_index.py` to update
      the html version.
    - Update the ``stable`` symlink to point to the released version.
    - Run ``git add`` for all the new files and commit.
    - Run ``git push`` to update the public version of the docs on gh-pages.
 
 #. Celebrate!