testSanitize fails in suite in release -2.1.8

[idella]

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ERROR: textile.tests.Tests.testSanitize
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Traceback (most recent call last):
  File "/usr/lib64/pypy/site-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/mnt/gen2/TmpDir/portage/app-text/pytextile-2.1.8/work/textile-2.1.8/textile/tests/__init__.py", line 474, in testSanitize
    expect = textile.Textile().textile(test, sanitize=True)
  File "/mnt/gen2/TmpDir/portage/app-text/pytextile-2.1.8/work/textile-2.1.8/textile/functions.py", line 290, in textile
    text = sanitizer.sanitize(text)
  File "/mnt/gen2/TmpDir/portage/app-text/pytextile-2.1.8/work/textile-2.1.8/textile/tools/sanitizer.py", line 16, in sanitize
    stream = walker(tree)
TypeError: 'NoneType' object is not callable

Name                      Stmts   Miss  Cover   Missing
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textile                       3      0   100%   
textile.functions           840     19    98%   32-33, 39-42, 216, 416-419, 485-486, 623-624, 895, 1073, 1237, 1465-1466
textile.tools               158    156     1%   9-264
textile.tools.imagesize      27     10    63%   15-16, 29, 33-34, 38-42
textile.tools.sanitizer      12      4    67%   9-10, 18-20
-------------------------------------------------------
TOTAL                      1040    189    82%   
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Ran 147 tests in 186.359s

FAILED (errors=1

This was a run under pypy. Consistent single fail of this test under py2.7 3.3 3.4 and pypy.
Do you require anything else?