[Python-modules-team] Bug#782795: python-pip: breaks with relocatable virtualenv, assert sys.prefix != real_prefix

[Filippo Giunchedi]

Package: python-pip
Version: 1.5.6-5
Severity: normal

hi,
it looks like pip stops working inside a virtualenv after using
virtualenv --relocatable

how to reproduce:

i7:/tmp$ virtualenv venv
Running virtualenv with interpreter /usr/bin/python2
New python executable in venv/bin/python2
Also creating executable in venv/bin/python
Installing setuptools, pip...done.
i7:/tmp$ venv/bin/pip install flask
Downloading/unpacking flask
  Downloading Flask-0.10.1.tar.gz (544kB): 544kB downloaded
  Running setup.py (path:/tmp/pip-build-IIMGrU/flask/setup.py) egg_info for package flask
[...]
Successfully installed flask Werkzeug Jinja2 itsdangerous markupsafe
Cleaning up...
i7:/tmp$ source venv/bin/activate
(venv)i7:/tmp$ virtualenv --relocatable venv
Running virtualenv with interpreter /tmp/venv/bin/python2
Making script venv/bin/pip2 relative
Making script venv/bin/easy_install-2.7 relative
Making script venv/bin/pip relative
Making script venv/bin/easy_install relative
Making script venv/bin/pip2.7 relative
(venv)i7:/tmp$ venv/bin/pip install flask
Traceback (most recent call last):
  File "venv/bin/pip", line 10, in <module>
    from pip import main
  File "/tmp/venv/local/lib/python2.7/site-packages/pip/__init__.py", line 39, in <module>
    assert sys.prefix != real_prefix
AssertionError
(venv)i7:/tmp$ 


-- System Information:
Debian Release: 8.0
  APT prefers testing-updates
  APT policy: (500, 'testing-updates'), (500, 'testing-proposed-updates'), (500, 'testing'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.19.0-trunk-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages python-pip depends on:
ii  ca-certificates       20141019
ii  python                2.7.9-1
ii  python-colorama       0.3.2-1
ii  python-distlib        0.1.9-1
ii  python-html5lib       0.999-3
ii  python-pkg-resources  5.5.1-1
ii  python-requests       2.4.3-6
ii  python-setuptools     5.5.1-1
ii  python-six            1.8.0-1
pn  python:any            <none>

Versions of packages python-pip recommends:
ii  build-essential  11.7
pn  python-dev-all   <none>
pn  python-wheel     <none>

python-pip suggests no packages.

-- no debconf information