Readline and Python 2.5+ on OS X

October 31, 2008

This is really just a “note to self” kind of post. I meant to write this down a while ago but I forgot. To prevent further forgetting, here it is:

I always compile Python myself. The Python that comes with OS X tends to get outdated pretty soon and it has outdated libraries in its site-packages directory. And beware installing or updating anything in there, it might ruin core components of OS X (because they actually use this Python instead of one that’s not the user’s to modify). I know that MacPorts too has various Python versions but it then again it applies various patches to them and builds them in weird manners that I don’t understand (framework, etc.). So the best bet to get a clean and reliable Python installation is to self-compile (and then use virtualenv to prevent it from being messed up).

As it happens, when I compiled Python 2.5 or higher on OS X, it linked to either the OS X readline library or the MacPorts one. Which one I don’t know, but it was definitely hosed. So while the interpreter worked fine, the interpreter shell would crash with a Bus Error. So what I did was compile my own plain vanilla version of readline and installed it to /opt. Of course that didn’t work right away because readline wouldn’t build on OS X Leopard without applying a small patch to a build script.

After having installed readline, I configured Python with the (undocumented, but apparently existing) --with-readline-dir option:

./configure --prefix=/opt --with-readline-dir=/opt

and did the usual make && make install dance.

4 Responses to “Readline and Python 2.5+ on OS X”

  1. Tom Lazar Says:

    Nice, but what I’d really want is to have a buildout that does all of the above in one go (including readline).

    any takers?

  2. Steve McMahon Says:

    Leopard actually uses libedit (which is broken in various ways) as a replacement for libreadline. My understanding is that this is a licensing matter: libedit is bsd, readline gpl.


  3. […] I have found out that Philipp von Weitershausen has written the post about the same problem I had a couple of weeks ago and was in the middle of writing the post about the same. Philipp has […]


  4. […] buildout to tame the snake pit After reading philiKON’s post about building Python 2.5 with readline on Mac OS X Leopard and getting my new MacBook Pro, I decided to create a buildout which does all the hard work and is […]


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