Hey, I've done a little writeup on why it doesn't work properly under Firefox (and some other little issues I ran into), and the fixes so that it should work all fine.
Got it here, if you'd like to have a look: http://pastebin.com/eZR2TSrC
80 karma · joined February 21, 2015
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Got it here, if you'd like to have a look: http://pastebin.com/eZR2TSrC
The issue I've usually had with it is just small things – maybe an module we depend on doesn't work with PyPy yet, maybe PyPy3 isn't 3.3-compatible yet and can't use "yield from", which we use in our code or which our libraries use.
Dealing with those sort of small issues (and/or waiting for PyPy to fix them), worrying about whether the project I'm currently working on can use PyPy or if I need to use CPython instead, etc makes me stop worrying about trying to use it after a while. In my dev environment at least.
I do really love what the PyPy guys are doing though, and when it works it works damn well. Building it from source is also super pretty.
Also great work on the project in general, PyPy has made Python work as a platform for a few previous projects where standard Python wouldn't have been usable.