You'll possibly find that you have another instance of GIMP already open with a file sufficiently large that you've put the process to sleep.
At least that's what I encountered.
- Launched gimp
- Received warning as above.
- Ran ps, discovered a sleeping gimp
- Killed sleeping gimp
- Relaunched gimp, warning reappears, but so does gimp as it should.
lev@isocracy:~/Desktop/webdev$ gimp
(gimp:25974): GLib-WARNING **: /build/buildd/glib2.0-2.30.0/./glib/goption.c:2168:
ignoring no-arg, optional-arg or filename flags (8) on option of type 0
lev@isocracy:~/Desktop/webdev$ ps afux | grep gimp
lev 21142 0.0 1.5 164356 32372 ? Sl Dec05 0:26 gimp-2.6 /home/lev/Desktop/newwebsitevpac.svg
lev 25976 0.0 0.0 4188 776 pts/2 S+ 15:08 0:00 _ grep gimp
lev@isocracy:~/Desktop/webdev$ kill 21142
lev@isocracy:~/Desktop/webdev$ gimp &
[1] 25982
lev@isocracy:~/Desktop/webdev$
(gimp:25982): GLib-WARNING **: /build/buildd/glib2.0-2.30.0/./glib/goption.c:2168: ignoring no-arg, optional-arg or filename flags (8) on option of type 0
px aux
, please. Because I think it's running, but the window just doesn't show up.