I repeated the above steps for ubuntu-18.04.2-live-server-amd64.iso, and got the same result. The regexp command in the grub shell does not work in secure boot mode. However, it does work in non-secure boot mode.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1829331 Title: Grub regexp command does not work in secure boot mode To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub-efi-amd64-signed/+bug/1829331/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs