Install debs manually and confirm that grub2 binaries in -proposed solve this problem.
GNU GRUB version 2.02~beta2-36ubuntu3.15
Minimal BASH-like line editing is supported. For the first word, TAB
lists possible command completions. Anywhere else TAB lists possible
device or file completions. ESC at any time exits.
grub> exit
Unloading driver at 0x00030F5F000
CoreLoadedImageInfo: Not an ImageHandle 3C1D0F18
grub2-signed in -proposed is in dependency wait.
Install debs manually and confirm that grub2 binaries in -proposed solve this problem.
Minimal BASH-like line editing is supported. For the first word, TAB
lists possible command completions. Anywhere else TAB lists possible
device or file completions. ESC at any time exits.
grub> exit Info: Not an ImageHandle 3C1D0F18
Unloading driver at 0x00030F5F000
CoreLoadedImage
Failed to boot both default and fallback entries.
Press any key to continue...