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 with (Any X LIMIT 10 WHERE X is Case)
Traceback (most recent call last)
File "c:\data\workspace\pyrene3\logilab\common\", line 645, in _proceed
testfunc(*args, **kwargs)
File "c:\data\workspace\pyrene3\cubicweb\devtools\", line 1076, in view
return self._test_view(viewfunc, view, template, kwargs)
File "c:\data\workspace\pyrene3\cubicweb\devtools\", line 1089, in _test_view
output = viewfunc(**kwargs)
File "c:\data\workspace\pyrene3\cubicweb\devtools\", line 1075, in <lambda>
rset=rset, **kwargs)
File "c:\data\workspace\pyrene3\cubicweb\", line 388, in main_template
res = obj.render(**kwargs)
File "c:\data\workspace\pyrene3\cubicweb\", line 137, in render
File "c:\data\workspace\pyrene3\cubes\squareui\views\", line 39, in call
File "c:\data\workspace\pyrene3\cubes\squareui\views\", line 80, in template_page_content
self.content_column(view, content_cols)
File "c:\data\workspace\pyrene3\cubes\squareui\views\", line 150, in content_column
File "c:\data\workspace\pyrene3\cubicweb\", line 137, in render
File "c:\data\workspace\pyrene3\cubicweb\", line 348, in call
super(EntityView, self).call(**kwargs)
File "c:\data\workspace\pyrene3\cubicweb\", line 187, in call
self.cell_call(row=0, **kwargs)
File "c:\data\workspace\pyrene3\cubicweb\web\views\", 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

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