[[!comment format=mdwn username="gueux" avatar="http://cdn.libravatar.org/avatar/2982bac2c2cd94ab3860efb189deafc8" subject="comment 1" date="2017-12-20T19:00:54Z" content=""" When I add a `File.dirExists \"/boot/efi\"` property, it goes further, but fails at the end: 0 100% 0.00kB/s 0:00:00 (xfr#0, to-chk=0/1) 26,454,269 100% 163.62MB/s 0:00:00 (xfr#5, to-chk=0/8) 770,765,173 99% 53.06MB/s 0:00:13 (xfr#26256, to-chk=0/33584) update-initramfs: Generating /boot/initrd.img-4.9.0-4-amd64 Installing for x86_64-efi platform. Installation finished. No error reported. Generating grub configuration file ... Found linux image: /boot/vmlinuz-4.9.0-4-amd64 Found initrd image: /boot/initrd.img-4.9.0-4-amd64 done umount: /tmp/mntAMcRoY/boot/efi: not mounted. ** fatal error: failed unmounting /tmp/mntAMcRoY/boot/efi ** warning: /tmp/mntAMcRoY: removeDirectoryRecursive:removeContentsRecursive:removeDirectory: resource busy (Device or resource busy) device-mapper: remove ioctl on loop0p3 failed: Device or resource busy loop deleted : /dev/loop0 laptop built disk image /srv/router.img ... failed laptop overall ... failed """]]