cubicweb-localperms #2110098 requires python-unittest2 to be installed [validation pending]

The localperms cube won't work if python-unittest2 is not installed on the computer:

INFO:cubicweb.cubes.pyrene.runner:starting job
Traceback (most recent call last):
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\cubes\pylos\runner_utils.py", line 67, in __init__
   status = self.run()
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\cubes\pylos\runner_utils.py", line 199, in run
   status = self._run()
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\cubes\pyrene\pyrene_runner.py", line 86, in _run
   curr_state = self.run_exec.in_state[0]
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\cubes\pylos\runner_utils.py", line 144, in run_exec
   self._run_exec = self.req.entity_from_eid(self.run_eid)
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\cubes\pylos\runner_utils.py", line 138, in req
   self._req = pyro_connect(self.instname, self.login, self.password, self.pyro_uri).request()
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\cubes\pylos\utils.py", line 40, in pyro_connect
   cnx.load_appobjects(cubes=cubes_to_load)
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\cubicweb\dbapi.py", line 580, in load_appobjects
   config.init_cubes(cubes)
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\cubicweb\cwconfig.py", line 833, in init_cubes
   self.load_site_cubicweb()
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\cubicweb\cwconfig.py", line 787, in load_site_cubicweb
   self._load_site_cubicweb(sitefile)
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\cubicweb\cwconfig.py", line 793, in _load_site_cubicweb
   module = load_module_from_modpath(modpath_from_file(sitefile, self.extrapath))
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\logilab\common\modutils.py", line 156, in load_module_from_modpath
   module = load_module(curname, mp_file, mp_filename, mp_desc)
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\cubes\localperms\site_cubicweb.py", line 34, in <module>
   from cubicweb.devtools import testlib
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\cubicweb\devtools\testlib.py", line 37, in <module>
   from logilab.common.testlib import TestCase, InnerTest, Tags
 File "\\NL1GRP1.melinda.local\PYL001A\Labo\Pyrene\logilab\common\testlib.py", line 65, in <module>
   sys.exit("You have to install python-unittest2 to use this module")
SystemExit: You have to install python-unittest2 to use this module
run failed

I would really appreciate if splitting out localperms could avoid adding external dependencies.

priorityimportant
typebug
done in0.1.1
load left0.000
closed by#034243f68d7c handle SystemExit rather than crashing (closes #2110098)