It removes --enable-more-warnings, since it is recommended to use --enable-compile-warnings=maximum It updates configure summary. It removes c++ checks as there is no c++ code.
g_variant_lookup works like g_variant_get, so using a format string of "v" only works if the type is actually a GVariant. Since none of the hints have GVariant values, that means every g_variant_get with a "v" format will fail. Fix all of the g_variant_lookup calls so that they either unpack a value directly, or use a "@" prefix when it's more convenient to fetch the value as a GVariant pointer. In addition, in cases where we do fetch a GVariant, make sure that we unreference it afterward.