PIP unnecessarily upgrades required packages

[chrisspen]

I encountered a problem while attempting to upgrade to django-table2 0.10.4 with pip install --upgrade django-tables2==0.10.4. The django-tables2 project requires Django 1.3 or later. Since I already had Django 1.3 installed, I expected pip to do nothing. However, pip incorrectly installed Django 1.4. I am not using a virtual environment.

Is this the correct behavior, and if so, how can I disable it?

If this behavior is intentional, I would argue that it should be changed since it's harmful to unnecessarily upgrade pre-installed dependencies. Even if the installed package claims a dependency can be safely upgraded, there's no guarantee that that dependency is not also used by other packages that require an older version. This was the case for me, and upgrading to Django 1.4 unexpectedly broke some of my code.

A temporary work around is to re-install Django 1.3 after the upgrade, but this is not a scalable solution in projects that may have dozens of dependencies.

[ejucovy]

This is a duplicate of #304, I think.

[chrisspen]

Yes, it does appear to be. Sorry for the dup.