Install libgmtk-dev by entering the following commands in the terminal:
sudo apt update sudo apt install libgmtk-dev
Description:
gnome-mplayer toolkit (development files)
A set of GTK+ widgets used by gnome-mplayer. It provides, amongst others, gnome-mplayer's media player widget. . This package provides the development files.
Homepage: http://code.google.com/p/gmtk/
Version: 1.0.9-2ubuntu1
Section: universe/libdevel