cubicweb #4399587 cwctl newcube does not work [open]

when used from properly installed debian packages:

david@perseus:~/hg/test$ cubicweb-ctl newcube mydemo -L full
Enter a short description for your cube: Demo
Traceback (most recent call last):
 File "/usr/bin/cubicweb-ctl", line 4, in <module>
   run(sys.argv[1:])
 File "/usr/lib/python2.7/dist-packages/cubicweb/cwctl.py", line 1110, in run
   CWCTL.run(args)
 File "/usr/lib/python2.7/dist-packages/logilab/common/clcommands.py", line 134, in run
   sys.exit(command.main_run(args, rcfile))
 File "/usr/lib/python2.7/dist-packages/logilab/common/clcommands.py", line 263, in main_run
   self.run(args)
 File "/usr/lib/python2.7/dist-packages/cubicweb/devtools/devctl.py", line 663, in run
   copy_skeleton(skeldir, cubedir, context, exclude=exclude)
 File "/usr/lib/python2.7/dist-packages/cubicweb/toolsutils.py", line 126, in copy_skeleton
   create_dir(tdirpath)
 File "/usr/lib/python2.7/dist-packages/cubicweb/toolsutils.py", line 60, in create_dir
   makedirs(directory)
 File "/usr/lib/python2.7/os.py", line 157, in makedirs
   mkdir(name, mode)
OSError: [Errno 13] Permission denied: '/usr/share/cubicweb/cubes/mydemo'
prioritynormal
typebug
done in<not specified>
closed by<not specified>