optional_depends gtk+3 \
                 '' HAVE_GTK= \
                 'for test-inspect' &&
optional_depends libxml2 \
                 '' HAVE_LIBXML= \
                 'for c2xml' &&
optional_depends llvm15 \
                 '' HAVE_LLVM= \
                 'for sparse-llvm' &&
optional_depends sqlite \
                 '' HAVE_SQLITE= \
                 'for semind (semantic indexer)'
