Error in activate script: _OLD_VIRTUAL_PYTHONHOME: unbound variable

[heartsucker]

• Pip version: 9.0.1
• Python version: 2.7.6
• Operating System: Ubuntu 14.04

Full system details.

root@ubuntu:~# pip --version
pip 9.0.1 from /usr/local/lib/python2.7/dist-packages (python 2.7)
root@ubuntu:~# python2.7 --version
Python 2.7.6
root@ubuntu:~# uname -a
Linux ubuntu 4.8.3-x86_64-linode76 #1 SMP Thu Oct 20 19:05:39 EDT 2016 x86_64 x86_64 x86_64 GNU/Linux
root@ubuntu:~# pip3 --version
pip 9.0.1 from /usr/local/lib/python3.4/dist-packages (python 3.4)
root@ubuntu:~# python3 --version
Python 3.4.3

Description:

I have a Debian package that has a postinst script that create a virtual environment, activates it, then installs some packages.

What I've run:

$ dpkg -i <my-deb>
...
...
Running virtualenv with interpreter /usr/bin/python3
Using base prefix '/usr'
New python executable in venv/bin/python3
Also creating executable in venv/bin/python
Installing setuptools, pip...done.
venv/bin/activate: line 13: _OLD_VIRTUAL_PYTHONHOME: unbound variable

[heartsucker]

I found the problem. It was an errant set -u floating around somewhere. Since the script expects the shell to allow undefined variables, I would recommend adding a set +u to the top to ensure that nothing breaks in other environments.

[ssbarnea]

This is closely related to pypa/virtualenv#150 and would have being avoided by using vate the virtual environment using a simple strict bash test.

#!/bin/bash
set -euo pipefail
IFS=$'\n\t'
source .venv/bin/activate

This would use the strict mode to test the activate script. My workaround line is endlessly growing PS1="${{PS1:-}}" _OLD_VIRTUAL_PATH="${{_OLD_VIRTUAL_PATH:-}}" _OLD_VIRTUAL_PYTHONHOME="${{_OLD_VIRTUAL_PYTHONHOME:-}}" source "$VENV/bin/activate" .... but now I get line 22: ZSH_VERSION: unbound variable....

[xavfernandez]

Not sure how it is pip related ?

[dstufft]

This looks to be a virtualenv issue and should be opened/discussed on the virtualenv tracker.