mousetweaks 3.2 fails to find libpanelapplet-3.0 (Bug #305)

$ sorcery -v
1.15.1-rc1

$ cat /var/lib/sorcery/codex/test/VERSION
0.61-test

1. cast mousetweaks
   Computing previously installed dependencies...
   mousetweaks preparing environment...
   mousetweaks running configuration...
   Build pointer-capture applet -> y
   Build dwell-click applet -> y
   ...
   checking for PANELAPPLET... no
   configure: error: Package requirements (libpanelapplet-3.0) were not met:

No package 'libpanelapplet-3.0' found

Prior libpanelappletmm comes from:
$ gaze from /usr/lib/libpanelappletmm-2.6.so
libpanelappletmm-2.26.0: /usr/lib/libpanelappletmm-2.6.so

$ gaze search -name libpanelapplet
libpanelapplet -> libpanelappletmm

https://bbs.archlinux.org/viewtopic.php?id=126721 has a similar issue with xmonad, but states that gnome-panel 2.32 contains libpanelapplet-3.0, but we have gnome-panel 3.2.1, which installs libpanelapplet-4.
$ gaze install gnome-panel | grep \/lib.*applet
/usr/include/gnome-panel-4.0/libpanel-applet
/usr/include/gnome-panel-4.0/libpanel-applet/panel-applet-enums.h
/usr/include/gnome-panel-4.0/libpanel-applet/panel-applet-gconf.h
/usr/include/gnome-panel-4.0/libpanel-applet/panel-applet.h
/usr/lib/libpanel-applet-4.la
/usr/lib/libpanel-applet-4.so
/usr/lib/libpanel-applet-4.so.0
/usr/lib/libpanel-applet-4.so.0.0.3
/usr/lib/pkgconfig/libpanelapplet-4.0.pc
/usr/libexec/clock-applet
/usr/libexec/fish-applet
/usr/libexec/notification-area-applet
/usr/libexec/wnck-applet