Upgrade to coverage 3.7.1 and have it auto-build itself on first use.

third_party/coverage-3.6/doc/trouble.rst

-.. _trouble:
-
-=========================
-Things that cause trouble
-=========================
-
-:history: 20121231T085200, brand new docs.
-
-Coverage works well, and I want it to properly measure any Python program, but
-there are some situations it can't cope with.  This page details some known
-problems, with possible courses of action, and links to coverage.py bug reports
-with more information.
-
-I would love to :ref:`hear from you <contact>` if you have information about any of
-these problems, even just to explain to me why you want them to start working
-properly.
-
-If your problem isn't discussed here, you can of course search the `coverage.py
-bug tracker`_ directly to see if there is some mention of it.
-
-.. _coverage.py bug tracker: https://bitbucket.org/ned/coveragepy/issues?status=new&status=open
-
-
-Things that don't work
-----------------------
-
-There are a number of popular modules, packages, and libraries that prevent
-coverage.py from working properly:
-
-* `execv`_, or one of its variants.  These end the current program and replace
-  it with a new one.  This doesn't save the collected coverage data, so your
-  program that calls execv will not be fully measured.  A patch for coverage.py
-  is in `issue 43`_.
-
-* `multiprocessing`_ launches processes to provide parallelism.  These
-  processes don't get measured by coverage.py.  Some possible fixes are
-  discussed or linked to in `issue 117`_.
-
-* `gevent`_, which is based on `greenlet`_, and is similar to `eventlet`_. All
-  of these manipulate the C stack, and therefore confuse coverage.py.
-  `Issue 149`_ has some pointers to more information.
-
-* `sys.settrace`_ is the Python feature that coverage.py uses to see what's
-  happening in your program.  If another part of your program is using
-  sys.settrace, then it will conflict with coverage.py, and it won't be
-  measured properly.
-
-.. _execv: http://docs.python.org/library/os#os.execl
-.. _multiprocessing: http://docs.python.org/library/multiprocessing.html
-.. _gevent: http://www.gevent.org/
-.. _greenlet: http://greenlet.readthedocs.org/
-.. _eventlet: http://eventlet.net/
-.. _sys.settrace: docs.python.org/library/sys.html#sys.settrace
-.. _issue 43: https://bitbucket.org/ned/coveragepy/issue/43/coverage-measurement-fails-on-code
-.. _issue 117: https://bitbucket.org/ned/coveragepy/issue/117/enable-coverage-measurement-of-code-run-by
-.. _issue 149: https://bitbucket.org/ned/coveragepy/issue/149/coverage-gevent-looks-broken
-
-
-Things that require --timid
----------------------------
-
-Some packages interfere with coverage measurement, but you might be able to
-make it work by using the ``--timid`` command-line switch, or the ``[run]
-timid=True`` configuration option.
-
-* `DecoratorTools`_, or any package which uses it, notably `TurboGears`_.
-  DecoratorTools fiddles with the trace function.  You  will need to use
-  ``--timid``.
-
-.. _DecoratorTools: http://pypi.python.org/pypi/DecoratorTools
-.. _TurboGears: http://turbogears.org/
-
-
-Really obscure things
----------------------
-
-* Python 2.5 had a bug (`1569356`_) that could make your program behave
-  differently when being measured with coverage.  This is diagnosed in `issue 51`_.
-
-.. _issue 51: http://bitbucket.org/ned/coveragepy/issue/51/turbogears-15-test-failing-with-coverage
-.. _1569356: http://bugs.python.org/issue1569356
-
-
-Still having trouble?
----------------------
-
-If your problem isn't mentioned here, and isn't already reported in the `coverage.py bug tracker`_,
-please :ref:`get in touch with me <contact>`, we'll figure out a solution.