The Ubuntu 20.04 installer supports a ZFS root filesystem, which works well until an install or update involves touching the grub configuration.
I have tracked down what looks like the root cause in /etc/grub.d/10_linux
What is the best way to contact one of the developers that works on grub?
Here's one easy way:
Test the development release of Ubuntu to see if the bug is still there. Lots of minor bugfixes don't get backported to older releases. If the bug is fixed, stop. Don't re-report a fixed problem. Instead, find the original bug report and request a Stable Release Update.
Figure out which package provides that file. In this example, you can see that the file
/etc/grub.d/10_linux
is provided by the packagegrub-common
File a bug report against the appropriate package using
ubuntu-bug <package_name>
and simply follow the prompts.After filing your bug report, ensure you get e-mail on that bug, so you can answer questions by Triagers and Developers on how to reproduce the problem in their test environment. Also, volunteers willing to test the fixes are essential.