Another way to disable rewrites?

I am trying to add a pytest plugin to coverage.py. Because the plugin is in the coverage package, coverage/init.py will be imported when the plugin is imported. Because I'm using coverage to run pytest in the first place, coverage/__init__.py has already been imported. This leads to a warning:

PytestAssertRewriteWarning: Module already imported so cannot be rewritten: coverage

I can disable this warning by adding PYTEST_DONT_REWRITE to the coverage/__init__.py docstring, but then that word is visible in the docstring for my package. Ugly.

Much of pytest is controlled by specially named attributes in modules. It would be great if I could control rewriting by adding an attribute to my module instead of amending the docstring.

If needed, I can provide a reproducer that shows the warning.

Start with the reported coverage/init.py setup and the PytestAssertRewriteWarning, then create the reproducer mentioned in the issue. Review pytest's assertion-rewrite handling to determine how a module attribute could control rewriting. Done means the warning can be disabled through a module attribute without adding PYTEST_DONT_REWRITE to the package docstring, with coverage's behavior preserved.