Modify tests to check unsupported forms of constraint

Clarify global and per-requirement options in pip install docs

Convert test_install_with_extras_from_install to not use URL constraint

Mark a few more tests as working under the new resolver

New resolver fix candidate ordering

Fix "src/pip" to respect flake8-bugbear

replace links to pypa-dev mailing list

 Add methods for path lookups in test_install_user.py and test_new_resolver_user.py

Add methods for path lookups in test_download.py and test_new_resolver.py

Add helper methods for path lookups to test_install_force_reinstall.py and test_uninstall_user.py

Add helper methods for path lookups to test_{uninstall, wheel}.py

Add methods for path lookups in test_install.py and test_install_compat.py

Add methods for path lookups in test_install_{vcs_git, wheel}.py

Add methods for path lookups in test_install_{extras, index}.py

Add methods for path lookups in test_install_{reqs, upgrade}.py

Pre-existing build directory fix

Extract supported req file option docs

Remove unused "pip._internal.utils.misc.cached_property"

Add flake8-bugbear plugin to pre-commit and fix "tests" accordingly

Parametrize test_install_package_to_usersite_with_target_must_fail

Remove new resolver marker from tests that should pass