Hello, For the record it seems Tobias had gotten around filing a bug here: https://github.com/lsof-org/lsof/issues/152.
It seems the issue is real and a new Linux-specific tool lsfd is being devised. I guess we should disable the test, as the package is still probably mostly functional on Btrfs, and wait for a proper resolution from upstream? Mark, could you share your patch disabling the test if you still have it handy? Thanks, Maxim