+ sudo chroot /var/www/build.openmodelica.org/virtual_machines/tmp-build/root apt-mark hold grub-pc grub-common grub-pc-bin grub2-common grub-efi-amd64-bin grub-efi-amd64-signed friendly-recovery grub-pc set on hold. grub-common set on hold. grub-pc-bin set on hold. grub2-common set on hold. grub-efi-amd64-bin set on hold. grub-efi-amd64-signed set on hold. friendly-recovery set on hold.