Created attachment 172316 [details]
this patches /usr/ports/Mk/Uses/gnome.mk to correct the gconftool-2 --makefile-unistall-rule that must execute BEFORE the port is uninstalled
when using gnome, or mate (http://mate-desktop.org) the ports uses gnome schemas but the framework on DEINSTALL phase tries to remove the schema from the gconf AFTER the port is deinstalled, but the schema is not there any more (was removed by the port because it is in the plist).
A fix of @postunexec to preunexec in the /usr/ports/Mk/Uses/gnome.mk resolves the issue
Please re-open if this is still an issue.