Damian Shaw

Interestingly this seems to turn `tests/test_resolvers.py::test_resolving_conflicts` into a flaky test. I think the only behavioral change that should have happened is that `get_preference` is not always called. I will need...

I have fixed the flaky test. The test relied on the order of resolution and this was broken by giving get_preference a set instead of a list. I got rid...

I have started to test the improvements using pip resolver branchmark: https://github.com/pradyunsg/pip-resolver-benchmarks The default benachmark of pyrax==1.9.8, moderetly improves from 4.75 +- 0.01 to 4.62 +- 0.04 on my machine....

I'm not really a fan of the name `filter_unsatisfied_names`, but I can't think of a better name right now.

Here is another example that produces `ResolutionTooDeep` in the current version of Pip: ``` sphinx sphinx-rtd-theme sphinx-toolbox myst-parser sphinxcontrib-bibtex nbsphinx ``` But can be solved by implementing this in resolvelib...

Working on the Pip implementation (https://github.com/pypa/pip/pull/12459), I realized it can be useful to have more than just backtrack_causes, so I have updated the `filter_unsatisfied_names` to basically mirror the `get_preference` arguments....

I've updated this PR based on the conversation here: https://github.com/pypa/pip/issues/12497 Main changes are: * `filter_unsatisfied_names` -> `narrow_backtrack_selection`, still would like a better name, but I think it addresses the concerns...

It occurs to me that resolvelib could validate that resolvelib could validate that the return value of `self._p.narrow_requirement_selection` is a subset of `unsatisfied_names`, this would guarantee that this method does...

> `PIP_CONFIG_FILE=pip.conf pip3 config set global.extra-index-url test` That doesn't look like a real file path, there should probably be a better error, but it looks like you're supplying invalid data.

From your orriginal message I thought you were saying the value of `PIP_CONFIG_FILE` is `pip.conf pip3 config set global.extra-index-url test`. Now I understand that was your entire shell command. I'm...