Install libags-gui-dev by entering the following commands in the terminal:
sudo apt update sudo apt install libags-gui-dev
Description:
Advanced Gtk+ Sequencer widget library (Development files)
libags_gui is a widget library built upon Gtk+-2.0. . This package includes the needed header files to develop with Advanced Gtk+ Sequencer UI widget library.
Homepage: https://nongnu.org/gsequencer
Version: 1.4.24-1ubuntu2
Section: universe/libdevel