Hi Maxim, > Yep, that did it. > > Fixed in aea756ea3312ba7e8229804492ba12001c8de568. this does not fix the build of lyx and twinkle for me, which both fail at 'qt-wrap: ---snip--- starting phase `qt-wrap' error: in phase 'qt-wrap': uncaught exception: wrong-type-arg "substring" "Wrong type argument in position ~A (expecting ~A): ~S" (1 "string" #f) (#f) phase `qt-wrap' failed after 0.0 seconds Backtrace: 9 (primitive-load "/gnu/store/gm47sv2ndfg906vkdr68nbv7zsi…") In guix/build/gnu-build-system.scm: 906:2 8 (gnu-build #:source _ #:outputs _ #:inputs _ #:phases . #) In ice-9/boot-9.scm: 1752:10 7 (with-exception-handler _ _ #:unwind? _ # _) In srfi/srfi-1.scm: 634:9 6 (for-each # …) In ice-9/boot-9.scm: 1752:10 5 (with-exception-handler _ _ #:unwind? _ # _) In guix/build/gnu-build-system.scm: 927:23 4 (_) In guix/build/qt-utils.scm: 148:22 3 (wrap-all-qt-programs #:inputs _ #:outputs _ #:qtbase _ …) In unknown file: 2 (string-drop #f 44) In ice-9/boot-9.scm: 1685:16 1 (raise-exception _ #:continuable? _) 1685:16 0 (raise-exception _ #:continuable? _) ice-9/boot-9.scm:1685:16: In procedure raise-exception: In procedure substring: Wrong type argument in position 1 (expecting string): #f ---snap--- Maybe a different incarnation of the same issue? Lars