depends gtk+2 &&
optional_depends exiv2 \
                 "--with-exiv2" \
                 "--without-exiv2" \
                 "exiv2 support" &&
optional_depends lcms \
                 "--with-lcms" \
                 "--without-lcms" \
                 "lcms support" &&
optional_depends libchamplain \
                 "" \
                 "" \
                 "support for displaying maps"
