[BUG] pip-accel 0.12.8 breaks Ubuntu compatibility about pip-accel

[xolox]

Just to be clear: You're talking about installing packages system wide, right? My intended use case for pip-accel is to bootstrap virtual environments, which is why I didn't notice this previously. Of course I'm not opposed to people using pip-accel to install system wide packages, so we can try to accommodate both use cases.

How I would like to see this fixed (if you want to create a pull request) is to detect which directories are available in the prefix that pip-accel is unpacking to and then rewrite filenames to use this directory scheme.

PS. For future reference, as pointed out by @fdv, the bug was introduced in cc06f65.

[fdv]

BTW, thank you for the awesome project, with a nightly generated (and packaged) cache, it reduced my deployment time from 25 to 7 minutes, AMI generation included.

[xolox]

Glad to hear that pip-accel is saving you time :-). I merged your pull request but changed the implementation, please refer to the pull request.

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A heads up, given that 1) you seem to be using pip-accel for serious work and 2) I recently broke pip-accel for you (in cc06f65): I just pushed b766ba2 which changes the system wide installation prefix from /usr to /usr/local on Debian (derived) systems. This could be considered a big change, but I think of it as a bug fix for an oversight on my part. Here is the comment I added to explain this change (if you're interested):

On Debian derived systems only apt (dpkg) should be allowed to touch files in /usr/lib/pythonX.Y/dist-packages/ and python setup.py install knows this (see the posix_local installation scheme in /usr/lib/python2.7/sysconfig.py on Debian systems). Because pip-accel replaces python setup.py install we have to replicate this logic. Magically inferring this from the sysconfig module would be nice but Python versions before 3.2 don't even have that module (it appears to be a Debian addition in versions before 3.2).

[xolox]

Thanks for the feedback and pull request! I believe this problem has been resolved for a while so will close this issue. If you encounter the problem again feel free to reopen this issue or report a new one.