pip install --pre airspeed now fails in virtual environment without version qualifier when installing latest

[billyjf]

Pip install is failing from within a new virtualenv, as shown below. Python version 2.7.6 on Ubuntu 14.04.1 LTS was used in this test.

The exact pattern shown below succeeded on airspeed-0.5.2dev-20150216.tar.gz, before today's update.

Using pip install --pre airspeed==0.5.3dev-20150421 seems to resolve the issue for Ubuntu virtual environments.

Strange that pip install --pre picks up macosx version of package on Ubuntu, but only within a virtualenv, not within global Python environment, which seems to pick the appropriate package.

Failing virtualenv test case on Ubuntu for install of latest:

root@saltmaster:# mkdir test_virtualenv
root@saltmaster:# virtualenv test_virtualenv
New python executable in test_virtualenv/bin/python
Installing setuptools, pip...done.
root@saltmaster:# source test_virtualenv/bin/activate
(test_virtualenv)root@saltmaster:# pip install --pre airspeed
Downloading/unpacking airspeed
Downloading airspeed-0.5.3dev-20150421.macosx-10.10-x86_64.tar.gz
Running setup.py (path:/root/test_virtualenv/build/airspeed/setup.py) egg_info for package airspeed
Traceback (most recent call last):
File "", line 17, in
IOError: [Errno 2] No such file or directory: '/root/test_virtualenv/build/airspeed/setup.py'
Complete output from command python setup.py egg_info:
Traceback (most recent call last):

File "", line 17, in

IOError: [Errno 2] No such file or directory: '/root/test_virtualenv/build/airspeed/setup.py'

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Cleaning up...
Command python setup.py egg_info failed with error code 1 in /root/test_virtualenv/build/airspeed
Storing debug log for failure in /root/.pip/pip.log