I believe the expected solution is to use the GRUB from the latest Ubuntu installed on such a disk, and let that GRUB boot older releases.
I am also not 100% sure if dual-booting two revisions of GRUB on one disk was ever a supported scenario anyhow (even on BIOS GRUB was installed to the MBR). Additionally no other UEFI aware OS seems to do what's proposed. Setting this to "Opinion" as this is a fundamental change on how the bootloader is installed, and should be proposed upstream instead. ** Changed in: grub2 (Ubuntu) Status: Triaged => Opinion -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1056101 Title: grub-efi overwrites an existing grub*.efi file To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1056101/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs