ctypes broken on armhf

[Loïc Minier]

Hi

Python's ctypes allows dynamically loading libraries. On linux, it parses ldconfig -p output for a given library name, skipping over incompatible ABIs. ABI is derived from uname output, which is incorrect. Currently, the code can't cope with "hard-float" in the ldconfig -p output on armhf.

I will attach a debdiff which allows ctypes to work on either armel or armhf, but wont work on a biarch or multiarch armel + armhf system.

The code should be redesigned to check the real ABI, not the uname output; one option to do so is to check the ABI of the currently running executable, e.g. ldd on sys.executable as done elsewhere in the script, but still seems fragile; another option is to look at /proc/$pid/maps (probably not portable); another option is to ask libc to do the loading (seems the safest).

Cheers,

[Matthias Klose (doko)]

won't fix for python2.6, to be removed

[Dr. David Alan Gilbert (davidgil-uk)]

Beware that ctypes may be broken in other ways on armhf as well; in particular it uses libffi to do its binding and a while ago when I looked I came to the conclusion it probably won't call variadic functions correctly if they are passed FP values.

My post to the ctypes list:
http://permalink.gmane.org/gmane.comp.python.ctypes/4657

[Launchpad Janitor (janitor)]

This bug was fixed in the package python2.7 - 2.7.2-8

---------------
python2.7 (2.7.2-8) unstable; urgency=low

  * Update to 20111130, taken from the 2.7 branch.
  * New patch, ctypes-arm, allow for ",hard-float" after libc6 in ldconfig -p
    output (Loic Minier). LP: #898172.
  * debian/rules: Define DPKG_VARS (Alban Browaeys). Closes: #647419).
  * Add python-config man page (Johann Felix Soden). Closes: #650181).

python2.7 (2.7.2-7) unstable; urgency=low

  * Adjust patches for removed Lib/plat-linux3.
  * Add build conflict to libncurses5-dev, let configure search for
    ncurses headers in /usr/include/ncursesw too.

python2.7 (2.7.2-6) unstable; urgency=low

  * Update to 20111004, taken from the 2.7 branch.
  * Use the ncursesw include directory when linking with ncursesw.
  * Rebuild with libreadline not linked with libncurses*. Closes: #643816.
  * Fix typos in the multiprocessing module. Closes: #643856.
 -- Matthias Klose <email address hidden> Thu, 01 Dec 2011 12:40:07 +0000

[Matthias Klose (doko)]

fixed in python3.2 3.2.2-1