libgxwmm-dev 0.38.1-1 (armhf binary) in ubuntu focal

 Guitarix is a rock guitar amplifier for the Jack Audio Connection Kit with
 one input and two outputs. It is designed to produce nice
 trash/metal/rock/blues guitar sounds and comes with a GTK+ interface and as
 Ladspa and LV2 plugins.
 .
 This package contains development files for Guitarix's GTK+ C++ widget library.