pip crashes with IndexError

[alex]

No idea what causes this, happy to take any steps to assist in reproducability:

(bb85a16c10916f30)Alexanders-MacBook-Pro:bb85a16c10916f30 alex_gaynor$ pip install --download=. colorama
Downloading/unpacking colorama
Cleaning up...
Exception:
Traceback (most recent call last):
  File "/Users/alex_gaynor/.virtualenvs/bb85a16c10916f30/lib/python2.7/site-packages/pip/basecommand.py", line 134, in main
    status = self.run(options, args)
  File "/Users/alex_gaynor/.virtualenvs/bb85a16c10916f30/lib/python2.7/site-packages/pip/commands/install.py", line 236, in run
    requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
  File "/Users/alex_gaynor/.virtualenvs/bb85a16c10916f30/lib/python2.7/site-packages/pip/req.py", line 1105, in prepare_files
    dist = list(pkg_resources.find_distributions(location))[0]
IndexError: list index out of range

[alex]

This is pip 1.4:

(bb85a16c10916f30)Alexanders-MacBook-Pro:bb85a16c10916f30 alex_gaynor$ pip --version
pip 1.4 from /Users/alex_gaynor/.virtualenvs/bb85a16c10916f30/lib/python2.7/site-packages (python 2.7)

[alex]

And my pip.conf:

(bb85a16c10916f30)Alexanders-MacBook-Pro:bb85a16c10916f30 alex_gaynor$ cat ~/.pip/pip.conf
[global]
timeout = 15
download_cache = ~/.pip/cache
allow-all-external = false
no-allow-insecure = false
use-wheel = true
wheel-dir = /Users/alex_gaynor/.pip/wheels
find-links = /Users/alex_gaynor/.pip/wheels

[dstufft]

Steps to reproduce:

$ pip wheel --wheel-dir ./wheelhouse colorama
$ pip install --use-wheel --find-links ./wheelhouse --download=. colorama

[qwcode]

pip install --download is not written to work with wheels. working on a fix with tests...

[qwcode]

there's 2 issues in the example @dstufft gives

1. --download doesn't work for wheels (the reason for the exception)
2. --download doesn't work correctly for local find-links in any case (which is an odd scenario, but it should either work or fail as invalid option combination)

I'm willing to fix 1) for the patch release (1.4.1), but 2) needs a fair amount of effort to fix correctly and fill in the gaps in unit testing. I'll log an issue for that.

[dstufft]

2. is probably getting exposed now because of people using find-links to expose a wheelhouse to pip install.

I think that's reasonable though.

[qwcode]

I use local find-links a lot (and the test suite does too). And we already recommend something similar here: http://www.pip-installer.org/en/latest/cookbook.html#fast-local-installs

Combining --download and local --find-links is odd because you're saying you want to download files you already have.

I don't think wheelhouse will make it more likely for someone to try to do this.

[dstufft]

Some folks are recommending people add --find-links=$WHEEL_DIR to the ~/.pip/pip.conf which means anyone who takes that advice will be using --find-links all the time in cases where they wouldn't have before.

[qwcode]

that's fine and only a problem if they then try to --download a requirement that will be fulfilled from those local dirs, which should still be uncommon

[qwcode]

closing. merged #1113