Hi, I notice that even if I used : package_ids_temp = pk_package_ids_to_text (package_ids, "|"); pk_backend_spawn_helper (spawn, "install-packages.pl", package_ids_temp, NULL); in my pk-backend-urpmi.c, install-packages.pl seems to be called like "install-packages.pl pkgid1 pkgid2 ..." instead of "install-packages.pl pkgid1|pkgid2|..." Aurélien.