Replace the on-screen-display volume level icon with a number.
Additionally, icon and number may be shown to the left and the right of the level bar:
Requires gnome-shell-extensions and gettext:
make install
OR automatically switch to the last supported release version before install make supported-install.
Install via $GUEST_SSHCMD on a virtual/remote host $GUEST_SSHADDR for debugging:
GUEST_SSHCMD=ssh GUEST_SSHADDR=guest@vm make debug-guest
Extract transalable text from sources to template file po/main.pot and update .po files:
make translations