Control: reassign -1 src:grub2 Control: found -1 2.04-10 Control: notfound -1 2.04-9 Control: found -1 2.02+dfsg1-20+deb10u3 Control: notfound -1 2.02+dfsg1-20+deb10u2
Turned out that the symptom was not specific to grub-efi. It does reproduce on grub-pc too. Short steps to test: 1) rename /bin/udevadm to something else 2) run grub-install {/dev/sda} 3) make sure no error has happened 4) look, all modules are gone! thanks very much.