Due to the compatibility issues with the GAFF parameters in latest ambertools, and openmmforcefields temporarily dropping support for it. See for example https://github.com/openmm/openmmforcefields/issues/327 . It is probably advisable to change the tests to use the latest OpenFF release instead of relying on GAFF to have a fully set of tests working in the CI.
Due to the compatibility issues with the GAFF parameters in latest
ambertools, andopenmmforcefieldstemporarily dropping support for it. See for example https://github.com/openmm/openmmforcefields/issues/327 . It is probably advisable to change the tests to use the latest OpenFF release instead of relying on GAFF to have a fully set of tests working in the CI.