Hello Pavel, > gnu/build/image.scm | 24 ++++++++++++++---------- > gnu/system/image.scm | 9 +++++++-- Please write a commit message following the guidelines available here: https://guix.gnu.org/manual/en/html_node/Submitting-Patches.html > +(define* (make-vfat-image partition target root fs_bits) s/fs_bits/fs-bits/ > + ((or (string=? file-system "vfat") (string=? file-system "fat16")) "0x0E") This line is longer than 78 characters you can break it between the two strings comparisons. > + ( > + (or (string=? file-system "vfat") Merge those two lines. > + (string=? file-system "fat32") > + ) "F") Ditto. Can you please send a v2? Thanks for your contribution, Mathieu