Python interactive segfaults on OS X 10.9 Mavericks

[Ned Deily]

Since OS X 10.9 Mavericks is now out, people are running into a severe problem 
when using some Python interpreters interactively.  The symptom is that the 
interpreter in interactive mode crashes after typing two lines:

$ python3.3
Python 3.3.2 (v3.3.2:d047928ae3f6, May 13 2013, 13:52:24)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> "Hello"  # first line OK
'Hello'
>>> "World"  # second line causes crash
Segmentation fault: 11

It does not matter what is entered on the two lines; the interpreter crashes 
after the second line.  The problem is caused by an upstream change in the OS 
X 10.9 editline library, libedit.  Most recent versions of the python.org 
installers dynamically link to the system-provided libedit and are susceptible 
to the problem.  These include Pythons from the following current installers:

3.3.2 64-bit/32-bit 10.6+
3.3.2 32-bit-only 10.5+
2.7.5 64-bit/32-bit 10.6+

Older releases of similar installers are also susceptible.  2.7.x Pythons from 
the 32-bit-only installers are not susceptible because they do not use 
libedit.  Pythons using GNU readline, including those with the PyPI readline 
distribution installed should not have problems.  Also, the Apple-supplied 
system Pythons (2.7.x, 2.6,x, and 2.5.x) shipped with OS X 10.9 do not exhibit 
the crash.  The problem is described in Issue18458.  It describes a 
workaround: disabling the readline extension by renaming or deleting it.  It 
also provides a script that can be downloaded to automate this "patching".

The fix for the problem has been released in the current 3.4.0a4 installers.  
It will be available in the installers for Python 3.3.3 and 2.7.6, which are 
expected to be released in the near future.  Release candidate installers for 
both should be available by Monday.

http://bugs.python.org/issue18458

Otherwise, for the most part, the transition to OS X 10.9 appears to be 
relatively problem-free so far.  Please open issues on the Python bug tracker 
for any new problems you encounter (after doing a quick search to see if it 
has already been reported!).

-- 
 Ned Deily,
 nad at acm.org