Subject: bug#21077: 24.5; Slow printing in inferior python buffer with python-shell-enable-font-lock

From: Stefan Monnier <[email-masked]>
Date: Fri, 17 Jul 2015 04:33:29 -0400

> It wasn't.  Something is clearly wrong with the regexps involved in
> this recipe, at least.

The trigger is simple and a well-known problem in Emacs: the command you
pass to Python outputs one very long line, and Emacs assumes at various places
that lines aren't too long.  One such assumption is in font-lock itself,
another appears to be in one of the regexps used in the font-lock config
of inferior python mode.

        Stefan