I don't think /etc/grub.d/bin/grubcfg_proxy is provided by an Ubuntu package or it is ancient. Where does it come from?
$ dpkg -S /etc/grub.d/bin/grubcfg_proxy ** Changed in: linux-signed (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2098890 Title: package linux-image-5.4.0-205-generic 5.4.0-205.225 failed to install/upgrade: run-parts: /etc/kernel/postinst.d/zz-update-grub exited with return code 127 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-signed/+bug/2098890/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs