Ok, there's nothing obviously wrong in that output. Can you please try the following commands:
sudo apt install strace sudo strace -ff -o /tmp/grub-install-trace -s 256 grub-install --target=x86_64-efi
And attach the resulting /tmp/grub-install-trace* files to this bug report?
Ok, there's nothing obviously wrong in that output. Can you please try the following commands:
sudo apt install strace install- trace -s 256 grub-install --target=x86_64-efi
sudo strace -ff -o /tmp/grub-
And attach the resulting /tmp/grub- install- trace* files to this bug report?