After reporting, I realized I'd forgotten to mark the partition as bootable. Doing so did not by itself solve the problem.
Contrary to https://help.ubuntu.com/community/UEFI ("Mount point: /boot/efi (remark: no need to set this mount point when using the manual partitioning, the Ubuntu installer will detect it automatically)"), explicitly specifying the mount point let the install proceed without problem. Perhaps that page could be corrected, and perhaps the installer could note the absence of an EFI system partition? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1562238 Title: grub-efi-amd64-siged failed to install To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub-installer/+bug/1562238/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
