cubicweb #7591935 useragent is None when running tests [open]

When running AutomaticWebTest on my app, I have a traceback concerning self._cw.useragent being None:

testing vid=network_graph_view defined in cubes.pyrene.views.network with (Any X LIMIT 10 WHERE X is Case)
----------------------------------------------------------------------
Traceback (most recent call last)
File "c:\data\workspace\pyrene3\logilab\common\testlib.py", line 645, in _proceed
testfunc(*args, **kwargs)
File "c:\data\workspace\pyrene3\cubicweb\devtools\testlib.py", line 1076, in view
return self._test_view(viewfunc, view, template, kwargs)
File "c:\data\workspace\pyrene3\cubicweb\devtools\testlib.py", line 1089, in _test_view
output = viewfunc(**kwargs)
File "c:\data\workspace\pyrene3\cubicweb\devtools\testlib.py", line 1075, in <lambda>
rset=rset, **kwargs)
File "c:\data\workspace\pyrene3\cubicweb\cwvreg.py", line 388, in main_template
res = obj.render(**kwargs)
File "c:\data\workspace\pyrene3\cubicweb\view.py", line 137, in render
view_func(**context)
File "c:\data\workspace\pyrene3\cubes\squareui\views\basetemplates.py", line 39, in call
self.template_page_content(view)
File "c:\data\workspace\pyrene3\cubes\squareui\views\basetemplates.py", line 80, in template_page_content
self.content_column(view, content_cols)
File "c:\data\workspace\pyrene3\cubes\squareui\views\basetemplates.py", line 150, in content_column
view.render(w=w)
File "c:\data\workspace\pyrene3\cubicweb\view.py", line 137, in render
view_func(**context)
File "c:\data\workspace\pyrene3\cubicweb\view.py", line 348, in call
super(EntityView, self).call(**kwargs)
File "c:\data\workspace\pyrene3\cubicweb\view.py", line 187, in call
self.cell_call(row=0, **kwargs)
File "c:\data\workspace\pyrene3\cubicweb\web\views\dotgraphview.py", line 39, in cell_call
if 'MSIE 8' in self._cw.useragent():
AssertionError: [<type 'exceptions.TypeError'> in network_graph_view] argument of type 'NoneType' is not iterable

The network_graph_view used in the failing test derives from cubicweb.web.views.dotgraphview.DotGraphView.

I am using CW 3.19.12

priorityminor
typebug
done in<not specified>
closed by<not specified>