case "$THIS_SUB_DEPENDS" in
  (BMFF)
    message "BMFF needed, forcing it." &&
    list_remove EXIV2_OPTS -DEXIV2_ENABLE_BMFF=OFF &&
    list_add EXIV2_OPTS -DEXIV2_ENABLE_BMFF=ON
    ;;
  (*)
    message "${PROBLEM_COLOR}bogus sub_depends: $SPELL $THIS_SUB_DEPENDS${DEFAULT_COLOR}"
    return 1
    ;;
esac
