If you test on ACL with the many variations that Dave set up (thanks, Dave!), there is a new problem: you end up testing upgrade over and over and over and over, and it takes forever.
This recent commit adds the ability to set ASDF_TEST_UPGRADE_LISPS, typically as a subset of ASDF_TEST_LISPS. If the variable is unset, it should not affect you (but this is not tested).
Best, r