I had some issues with Python when trying to upgrade PostgreSQL install on OSX Lion.
Basically the configure script is saying that my system version of Python doesn't have 64-bit support.
Warning: Detected a framework Python that does not have 64-bit support in:
To fix this issue, you may need to either delete the version of Python shown above, or move it out of the way before brewing PostgreSQL.
I don't like those solutions very much, and I don't need Python support in Postgres anyway. To get around the problem and build Postgres without Python support at all, just...
brew upgrade --no-python postgresql
Muskets at dawn!