Python trace hooks are somewhat buggy.
$ trial --coverage nevow.test.test_rend.TestPage.test_missingRendererDeprecated
Setting coverage directory to coverage.
Running 1 tests.
nevow.test.test_rend
TestPage
test_missingRendererDeprecated ... [ERROR]
===============================================================================
[ERROR]: nevow.test.test_rend.TestPage.test_missingRendererDeprecated
Traceback (most recent call last):
File "/home/exarkun/Projects/Divmod/trunk/Nevow/nevow/test/test_rend.py", line 479, in test_missingRendererDeprecated
page.renderSynchronously)
File "/home/exarkun/Projects/Twisted/trunk/twisted/trial/unittest.py", line 346, in failUnlessWarns
result = f(*args, **kwargs)
File "/home/exarkun/Projects/Divmod/trunk/Nevow/nevow/rend.py", line 614, in renderSynchronously
list(flat.iterflatten(doc, ctx, io.write, raiseAlways))
File "/home/exarkun/Projects/Divmod/trunk/Nevow/nevow/flat/ten.py", line 83, in iterflatten
for item in gen:
File "/home/exarkun/Projects/Divmod/trunk/Nevow/nevow/flat/flatstan.py", line 103, in TagSerializer
yield serialize(toBeRenderedBy, context)
File "/home/exarkun/Projects/Divmod/trunk/Nevow/nevow/flat/ten.py", line 70, in serialize
return partialflatten(context, obj)
File "/home/exarkun/Projects/Divmod/trunk/Nevow/nevow/flat/ten.py", line 61, in partialflatten
return flattener(obj, context)
File "/home/exarkun/Projects/Divmod/trunk/Nevow/nevow/flat/flatstan.py", line 263, in DirectiveSerializer
renderer = rendererFactory.renderer(context, original.name)
exceptions.TypeError: 'str' object is not callable
-------------------------------------------------------------------------------
Ran 1 tests in 0.101s
FAILED (errors=1)
Related: #2392, #2394