ContextualVersionConflict on requirement to re-install when no egg_info and --process-dependency-links

• Pip version: 9.0.1
• Python version: 2.7.12
• Operating system: Ubuntu 16.04

Description:

In a particular case, unexpected ContextualVersionConflict occurs.

$ pip install --process-dependency-links -e .
Obtaining file:///.../pip-issue-4537
Exception:
Traceback (most recent call last):
  ...
ContextualVersionConflict: (simplejson 3.9.0 (.../env/lib/python2.7/site-packages), Requirement.parse('simplejson==3.10.0'), set(['pip-issue-4537']))

The conditions are:

• pip==9.0.1 (no problem in 8.1.2)
• The package to be installed has a dependency. The dependent package was already installed but different version. So it should be upgraded.
• Use --process-dependency-links option.
• Use -e option.
• No egg_info directory yet.

What I’ve run:

Here’s the steps to reproduce this issue:

$ pip install pip==9.0.1
$ mkdir pip-issue-4537
$ cd pip-issue-4537
$ echo "from setuptools import setup" > setup.py
$ echo "setup(name='pip-issue-4537', install_requires=['simplejson==3.10.0'])" >> setup.py
$ pip install simplejson==3.9.0
$ pip install --process-dependency-links -e .
Obtaining file:///.../pip-issue-4537
Exception:
Traceback (most recent call last):
  ...
ContextualVersionConflict: (simplejson 3.9.0 (.../env/lib/python2.7/site-packages), Requirement.parse('simplejson==3.10.0'), set(['pip-issue-4537']))

But if we have a egg_info directory, this error doesn’t occur:

$ python setup.py install_egg_info
$ pip install --process-dependency-links -e .
Obtaining file:///.../pip-issue-4537
Exception:
Traceback (most recent call last):
  ...
ContextualVersionConflict: (simplejson 3.9.0 (.../env/lib/python2.7/site-packages), Requirement.parse('simplejson==3.10.0'), set(['pip-issue-4537']))

[mastak]

Hi,

We encounter this at Circleci. As a workaround you can make egg-info before:

python setup.py install_egg_info
pip install -e .

[NotSqrt]

Hi,

In case someone else encounters this situation:

I faced this issue on Gitlab CI when reusing the same virtualenv between builds. When the previous build had run pip install -e ., the corresponding *.egg-info/ is cleaned up at the start of the next build, which will result in ContextualVersionConflict exception when running pip install -e ..

By removing the *.egg-link file in the reused virtualenv, I can rerun pip install -e . without problems.

Thanks !

---

Edit: The most reliable way : pip remove the packages installed as -e on CI clean-up (after_script with Gitlab CI).