Hey Jan, > (system (current-system)) > (target (operating-system-derivation target-os)) > - (base-image (find-image > - installation-disk-image-file-system-type)) > + (base-image -> (find-image > + installation-disk-image-file-system-type > + (%current-target-system))) This should be: --8<---------------cut here---------------start------------->8--- (target (current-target-system)) ... (base-image -> (find-image installation-disk-image-file-system-type target)) --8<---------------cut here---------------end--------------->8--- > + ((image -> (find-image file-system-type (%current-target-system))) > (sys (system-derivation-for-action os image action > #:file-system-type file-system-type > #:image-size image-size Same here, otherwise this look good to me. Thanks, Mathieu