Pulp

Consider the following scenario:

1. Pulp 3.2.1 & pulp-file 0.2 were installed.
2. The user runs the latest pulp_installer (3.3), to upgrade pulpcore (3.3), and pulp-file (0.3).
3. The user specifies to install pulp-file in pulp_install_plugins, and includes "upgrade:true ". This instructs the installer to upgrade pulp-file to the latest version, which is currently 0.3.

This causes the following to happen

1. /usr/local/lib/pulp/requirements.txt exists and contains pulp-file==0.2
2. pip-compile sees "pulp-file" in requirements.in that pulp_installer generates, but has no further instructions to upgrade pulp-file.
3. pip-compile produces the following error, and the installer fails:

There are incompatible versions in the resolved dependencies:
  pulpcore==3.3.0 (from -r requirements.in (line 1))
  pulpcore<3.3,>=3.0 (from pulp-file==0.2.0->-r requirements.in (line 2))

4. However, if the pre-flight check was ignored, the install would have succeeded, because pulp-file would have been upgraded actually.

Users can work around this currently by specifying "version" for the plugin.

We can fix this by running a pre-flight command like: pip-compile -P pulp-file or if multiple plugins are specified to be upgraded: pip-compile -P pulp-file -P pulp-container This is in addition to the requirements.in existing like it currently does.

I confirmed that this will fix this with a venv, starting with these packages installed: pip install pulp-container==1.2.0 pulp-file==0.2.0 pip install pulp-container==1.2.0 pulp-file==0.2.0 pulpcore==3.2.1