bzr's doctests are not isolated (branchbuilder doctests check global gpg configuration)

A good fix would probably be to change the way we construct DocTestSuite. We could pass setUp and tearDown params to its constructor to do the same sort of setUp and tearDown as we do in normal TestCases. In particular do the isolation of the test environment from the user's normal day-to-day environment.

(It might be neat to also provide an addCleanup facility in the globs param, too, but that's a separate issue.)

This annoys anyone who runs the full test suite and has gpg signing defaulted to true.

Probably also this bug, in some slightly mysterious circumstances that depends on my particular test setup and on what other tests are also run, I get this failure:

File ".\bzrlib\branchbuilder.py", line 42, in bzrlib.branchbuilder.BranchBuilder
Failed example:
    builder.build_snapshot('rev-id', None, [
        ('add', ('', 'root-id', 'directory', '')),
        ('add', ('filename', 'f-id', 'file', 'content\n'))])
Exception raised:
    Traceback (most recent call last):
      File "...\python-trunk\lib\doctest.py", line 1248, in __run
        compileflags, 1) in test.globs
      File "<doctest bzrlib.branchbuilder.BranchBuilder[3]>", line 3, in <module>
        ('add', ('filename', 'f-id', 'file', 'content\n'))])
      File ".\bzrlib\branchbuilder.py", line 250, in build_snapshot
        message_callback=message_callback)
      File ".\bzrlib\branchbuilder.py", line 112, in _do_commit
        **kwargs)
      File "<string>", line 4, in commit_write_locked
      File ".\bzrlib\mutabletree.py", line 200, in commit
        *args, **kwargs)
      File ".\bzrlib\commit.py", line 286, in commit
        possible_master_transports=possible_master_transports)
      File ".\bzrlib\cleanup.py", line 131, in run
        self.cleanups, self.func, self, *args, **kwargs)
      File ".\bzrlib\cleanup.py", line 165, in _do_with_cleanups
        result = func(*args, **kwargs)
      File ".\bzrlib\commit.py", line 402, in _commit
        self.config, timestamp, timezone, committer, self.revprops, rev_id)
      File ".\bzrlib\branch.py", line 704, in get_commit_builder
        timestamp, timezone, committer, revprops, revision_id)
      File ".\bzrlib\repository.py", line 1765, in get_commit_builder
        timestamp, timezone, committer, revprops, revision_id)
      File ".\bzrlib\repofmt\pack_repo.py", line 117, in __init__
        revprops=revprops, revision_id=revision_id)
      File ".\bzrlib\repository.py", line 114, in __init__
        self._committer = self._config.username()
      File ".\bzrlib\config.py", line 279, in username
        raise errors.NoWhoami()
    NoWhoami: Unable to determine your name.
    Please, set your name with the 'whoami' command.
    E.g. bzr whoami "Your Name <email address hidden>"

Nice catch, please add a setup and teardown that isolate appropriately
to the doctest factory in tests/__init__.py.

-Rob

With bug #690563 fixed, the doctest in bzrlib.branchbuiler is now failing on pqm.

I've commented out bzrlib.branchbuilder in bzrlib.tests.__init__.py with a FIXME mentioning this bug.

Whoever ends up fixing *this* bug should make sure to uncomment the line.