Merged in rogerjhu/coverage.py (pull request #19)

Make UTF-8 detection more robust.

31 files changed, 767 insertions, 372 deletions

diff --git a/.hgignore b/.hgignore
index d8b5935..34fa8a7 100644
--- a/.hgignore
+++ b/.hgignore
@@ -1,32 +1,32 @@
-syntax: glob

-

-# Files that can appear anywhere in the tree.

-*.pyc

-*.pyo

-*$py.class

-*.pyd

-*.so

-*.bak

-.coverage

-.coverage.*

-*.swp

-

-# Stuff generated by editors.

-.idea/

-

-# Stuff in the root.

-build

-*.egg-info

-dist

-htmlcov

-MANIFEST

-setuptools-*.egg

-.tox

-.tox_kits

-

-# Stuff in the test directory.

-zipmods.zip

-

-# Stuff in the doc directory.

-_build

-sample_html_beta

+syntax: glob
+
+# Files that can appear anywhere in the tree.
+*.pyc
+*.pyo
+*$py.class
+*.pyd
+*.so
+*.bak
+.coverage
+.coverage.*
+*.swp
+
+# Stuff generated by editors.
+.idea/
+
+# Stuff in the root.
+build
+*.egg-info
+dist
+htmlcov
+MANIFEST
+setuptools-*.egg
+.tox
+.tox_kits
+
+# Stuff in the test directory.
+zipmods.zip
+
+# Stuff in the doc directory.
+_build
+sample_html_beta
diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..2dfd698
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,21 @@
+# Tell Travis what to do
+# https://travis-ci.org/nedbat/coveragepy
+
+language: python
+
+python:
+  - 2.5
+  - 2.6
+  - 2.7
+  - 3.2
+  - 3.3
+  - pypy
+
+install:
+  - python setup.py clean develop
+
+script:
+  - python igor.py zip_mods install_egg
+  - python igor.py test_with_tracer c
+  - python igor.py remove_extension
+  - python igor.py test_with_tracer py
diff --git a/CHANGES.txt b/CHANGES.txt
index 316df0c..47976b3 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -5,7 +5,10 @@ Change history for Coverage.py
 3.6.1
 -----
 
-- Improved the branch coverage mechanism, fixing `issue 175`_.
+- Added the ``--debug`` switch to ``coverage run``.  It accepts a list of
+  options indicating the type of internal activity to log to stderr.
+
+- Improved the branch coverage facility, fixing `issue 92`_ and `issue 175`_.
 
 - Running code with ``coverage run -m`` now behaves more like Python does,
   setting sys.path properly, which fixes `issue 207`_ and `issue 242`_.
@@ -14,15 +17,20 @@ Change history for Coverage.py
   cause them to be incorrectly marked as unexecuted, as described in
   `issue 218`_.  This is now fixed.
 
-- When running a threaded program under the Python tracer, coverage would issue
-  a spurious warning about the trace function changing: "Trace function
-  changed, measurement is likely wrong: None." This fixes `issue 164`_.
+- When running a threaded program under the Python tracer, coverage no longer
+  issues a spurious warning about the trace function changing: "Trace function
+  changed, measurement is likely wrong: None."  This fixes `issue 164`_.
+
+- The source kit now includes the `__main__.py` file in the root coverage
+  directory, fixing `issue 255`_.
 
+.. _issue 92: https://bitbucket.org/ned/coveragepy/issue/92/finally-clauses-arent-treated-properly-in
 .. _issue 164: https://bitbucket.org/ned/coveragepy/issue/164/trace-function-changed-warning-when-using
 .. _issue 175: https://bitbucket.org/ned/coveragepy/issue/175/branch-coverage-gets-confused-in-certain
 .. _issue 207: https://bitbucket.org/ned/coveragepy/issue/207/run-m-cannot-find-module-or-package-in
 .. _issue 242: https://bitbucket.org/ned/coveragepy/issue/242/running-a-two-level-package-doesnt-work
 .. _issue 218: https://bitbucket.org/ned/coveragepy/issue/218/run-command-does-not-respect-the-omit-flag
+.. _issue 255: https://bitbucket.org/ned/coveragepy/issue/255/directory-level-__main__py-not-included-in
 
 
 Version 3.6 --- 5 January 2013
diff --git a/MANIFEST.in b/MANIFEST.in
index d2712d9..7224674 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -4,6 +4,7 @@ recursive-include coverage/fullcoverage *
 
 include coverage.egg-info/*.*
 include setup.py
+include __main__.py
 include README.txt
 include CHANGES.txt
 include AUTHORS.txt
diff --git a/Makefile b/Makefile
index 0588105..1ce7497 100644
--- a/Makefile
+++ b/Makefile
@@ -48,7 +48,9 @@ metahtml:
 
 # Kitting
 
-SDIST_CMD = python setup.py sdist --keep-temp --formats=gztar fixtar --owner=ned --group=coverage --clean
+# For kitting on Windows:
+# SDIST_CMD = python setup.py sdist --keep-temp --formats=gztar fixtar --owner=ned --group=coverage --clean
+SDIST_CMD = python setup.py sdist --formats=gztar
 
 kit:
 	$(SDIST_CMD)
diff --git a/coverage/__init__.py b/coverage/__init__.py
index 0ccc699..193b7a1 100644
--- a/coverage/__init__.py
+++ b/coverage/__init__.py
@@ -92,7 +92,7 @@ except KeyError:
 # COPYRIGHT AND LICENSE
 #
 # Copyright 2001 Gareth Rees.  All rights reserved.
-# Copyright 2004-2012 Ned Batchelder.  All rights reserved.
+# Copyright 2004-2013 Ned Batchelder.  All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
diff --git a/coverage/cmdline.py b/coverage/cmdline.py
index ac80310..0881313 100644
--- a/coverage/cmdline.py
+++ b/coverage/cmdline.py
@@ -5,6 +5,7 @@ import optparse, os, sys, traceback
 from coverage.backward import sorted                # pylint: disable=W0622
 from coverage.execfile import run_python_file, run_python_module
 from coverage.misc import CoverageException, ExceptionDuringRun, NoSource
+from coverage.debug import info_formatter
 
 
 class Opts(object):
@@ -19,6 +20,10 @@ class Opts(object):
         '', '--branch', action='store_true',
         help="Measure branch coverage in addition to statement coverage."
         )
+    debug = optparse.make_option(
+        '', '--debug', action='store', metavar="OPTS",
+        help="Debug options, separated by commas"
+        )
     directory = optparse.make_option(
         '-d', '--directory', action='store', metavar="DIR",
         help="Write the output files to DIR."
@@ -117,6 +122,7 @@ class CoverageOptionParser(optparse.OptionParser, object):
         self.set_defaults(
             actions=[],
             branch=None,
+            debug=None,
             directory=None,
             fail_under=None,
             help=None,
@@ -310,6 +316,7 @@ CMDS = {
         [
             Opts.append,
             Opts.branch,
+            Opts.debug,
             Opts.pylib,
             Opts.parallel_mode,
             Opts.module,
@@ -404,6 +411,7 @@ class CoverageScript(object):
         source = unshell_list(options.source)
         omit = unshell_list(options.omit)
         include = unshell_list(options.include)
+        debug = unshell_list(options.debug)
 
         # Do something.
         self.coverage = self.covpkg.coverage(
@@ -415,6 +423,7 @@ class CoverageScript(object):
             source = source,
             omit = omit,
             include = include,
+            debug = debug,
             )
 
         if 'debug' in options.actions:
@@ -584,16 +593,8 @@ class CoverageScript(object):
         for info in args:
             if info == 'sys':
                 print("-- sys ----------------------------------------")
-                for label, info in self.coverage.sysinfo():
-                    if info == []:
-                        info = "-none-"
-                    if isinstance(info, list):
-                        prefix = "%15s:" % label
-                        for e in info:
-                            print("%16s %s" % (prefix, e))
-                            prefix = ""
-                    else:
-                        print("%15s: %s" % (label, info))
+                for line in info_formatter(self.coverage.sysinfo()):
+                    print(" %s" % line)
             elif info == 'data':
                 print("-- data ---------------------------------------")
                 self.coverage.load()
diff --git a/coverage/collector.py b/coverage/collector.py
index 781a0fa..9a74700 100644
--- a/coverage/collector.py
+++ b/coverage/collector.py
@@ -75,10 +75,11 @@ class PyTracer(object):
             # in this file.
             self.data_stack.append((self.cur_file_data, self.last_line))
             filename = frame.f_code.co_filename
-            tracename = self.should_trace_cache.get(filename)
-            if tracename is None:
+            if filename not in self.should_trace_cache:
                 tracename = self.should_trace(filename, frame)
                 self.should_trace_cache[filename] = tracename
+            else:
+                tracename = self.should_trace_cache[filename]
             #print("called, stack is %d deep, tracename is %r" % (
             #               len(self.data_stack), tracename))
             if tracename:
@@ -166,7 +167,7 @@ class Collector(object):
         """Create a collector.
 
         `should_trace` is a function, taking a filename, and returning a
-        canonicalized filename, or False depending on whether the file should
+        canonicalized filename, or None depending on whether the file should
         be traced or not.
 
         If `timid` is true, then a slower simpler trace function will be
@@ -210,7 +211,7 @@ class Collector(object):
 
         # A cache of the results from should_trace, the decision about whether
         # to trace execution in a file. A dict of filename to (filename or
-        # False).
+        # None).
         self.should_trace_cache = {}
 
         # Our active Tracers.
diff --git a/coverage/config.py b/coverage/config.py
index c2ebecb..87318ff 100644
--- a/coverage/config.py
+++ b/coverage/config.py
@@ -111,6 +111,7 @@ class CoverageConfig(object):
         self.parallel = False
         self.timid = False
         self.source = None
+        self.debug = []
 
         # Defaults for [report]
         self.exclude_list = DEFAULT_EXCLUDE[:]
@@ -142,7 +143,7 @@ class CoverageConfig(object):
         if env:
             self.timid = ('--timid' in env)
 
-    MUST_BE_LIST = ["omit", "include"]
+    MUST_BE_LIST = ["omit", "include", "debug"]
 
     def from_args(self, **kwargs):
         """Read config values from `kwargs`."""
@@ -178,6 +179,7 @@ class CoverageConfig(object):
         ('branch', 'run:branch', 'boolean'),
         ('cover_pylib', 'run:cover_pylib', 'boolean'),
         ('data_file', 'run:data_file'),
+        ('debug', 'run:debug', 'list'),
         ('include', 'run:include', 'list'),
         ('omit', 'run:omit', 'list'),
         ('parallel', 'run:parallel', 'boolean'),
diff --git a/coverage/control.py b/coverage/control.py
index 8821bfb..4b76121 100644
--- a/coverage/control.py
+++ b/coverage/control.py
@@ -3,11 +3,12 @@
 import atexit, os, random, socket, sys
 
 from coverage.annotate import AnnotateReporter
-from coverage.backward import string_class, iitems
+from coverage.backward import string_class, iitems, sorted  # pylint: disable=W0622
 from coverage.codeunit import code_unit_factory, CodeUnit
 from coverage.collector import Collector
 from coverage.config import CoverageConfig
 from coverage.data import CoverageData
+from coverage.debug import DebugControl
 from coverage.files import FileLocator, TreeMatcher, FnmatchMatcher
 from coverage.files import PathAliases, find_python_files, prep_patterns
 from coverage.html import HtmlReporter
@@ -17,6 +18,14 @@ from coverage.results import Analysis, Numbers
 from coverage.summary import SummaryReporter
 from coverage.xmlreport import XmlReporter
 
+# Pypy has some unusual stuff in the "stdlib".  Consider those locations
+# when deciding where the stdlib is.
+try:
+    import _structseq       # pylint: disable=F0401
+except ImportError:
+    _structseq = None
+
+
 class coverage(object):
     """Programmatic access to coverage.py.
 
@@ -33,7 +42,8 @@ class coverage(object):
     """
     def __init__(self, data_file=None, data_suffix=None, cover_pylib=None,
                 auto_data=False, timid=None, branch=None, config_file=True,
-                source=None, omit=None, include=None):
+                source=None, omit=None, include=None, debug=None,
+                debug_file=None):
         """
         `data_file` is the base name of the data file to use, defaulting to
         ".coverage".  `data_suffix` is appended (with a dot) to `data_file` to
@@ -68,6 +78,10 @@ class coverage(object):
         `include` will be measured, files that match `omit` will not.  Each
         will also accept a single string argument.
 
+        `debug` is a list of strings indicating what debugging information is
+        desired. `debug_file` is the file to write debug messages to,
+        defaulting to stderr.
+
         """
         from coverage import __version__
 
@@ -100,9 +114,12 @@ class coverage(object):
         self.config.from_args(
             data_file=data_file, cover_pylib=cover_pylib, timid=timid,
             branch=branch, parallel=bool_or_none(data_suffix),
-            source=source, omit=omit, include=include
+            source=source, omit=omit, include=include, debug=debug,
             )
 
+        # Create and configure the debugging controller.
+        self.debug = DebugControl(self.config.debug, debug_file or sys.stderr)
+
         self.auto_data = auto_data
 
         # _exclude_re is a dict mapping exclusion list names to compiled
@@ -147,7 +164,8 @@ class coverage(object):
         # started rather than wherever the process eventually chdir'd to.
         self.data = CoverageData(
             basename=self.config.data_file,
-            collector="coverage v%s" % __version__
+            collector="coverage v%s" % __version__,
+            debug=self.debug,
             )
 
         # The dirs for files considered "installed with the interpreter".
@@ -158,8 +176,8 @@ class coverage(object):
             # environments (virtualenv, for example), these modules may be
             # spread across a few locations. Look at all the candidate modules
             # we've imported, and take all the different ones.
-            for m in (atexit, os, random, socket):
-                if hasattr(m, "__file__"):
+            for m in (atexit, os, random, socket, _structseq):
+                if m is not None and hasattr(m, "__file__"):
                     m_dir = self._canonical_dir(m)
                     if m_dir not in self.pylib_dirs:
                         self.pylib_dirs.append(m_dir)
@@ -168,7 +186,7 @@ class coverage(object):
         # where we are.
         self.cover_dir = self._canonical_dir(__file__)
 
-        # The matchers for _should_trace, created when tracing starts.
+        # The matchers for _should_trace.
         self.source_match = None
         self.pylib_match = self.cover_match = None
         self.include_match = self.omit_match = None
@@ -201,26 +219,28 @@ class coverage(object):
                 filename = filename[:-9] + ".py"
         return filename
 
-    def _should_trace(self, filename, frame):
-        """Decide whether to trace execution in `filename`
+    def _should_trace_with_reason(self, filename, frame):
+        """Decide whether to trace execution in `filename`, with a reason.
 
         This function is called from the trace function.  As each new file name
         is encountered, this function determines whether it is traced or not.
 
-        Returns a canonicalized filename if it should be traced, False if it
-        should not.
+        Returns a pair of values:  the first indicates whether the file should
+        be traced: it's a canonicalized filename if it should be traced, None
+        if it should not.  The second value is a string, the resason for the
+        decision.
 
         """
         if not filename:
             # Empty string is pretty useless
-            return False
+            return None, "empty string isn't a filename"
 
         if filename.startswith('<'):
             # Lots of non-file execution is represented with artificial
             # filenames like "<string>", "<doctest readme.txt[0]>", or
             # "<exec_function>".  Don't ever trace these executions, since we
             # can't do anything with the data later anyway.
-            return False
+            return None, "not a real filename"
 
         self._check_for_packages()
 
@@ -246,35 +266,41 @@ class coverage(object):
         # stdlib and coverage.py directories.
         if self.source_match:
             if not self.source_match.match(canonical):
-                return False
+                return None, "falls outside the --source trees"
         elif self.include_match:
             if not self.include_match.match(canonical):
-                return False
+                return None, "falls outside the --include trees"
         else:
             # If we aren't supposed to trace installed code, then check if this
             # is near the Python standard library and skip it if so.
             if self.pylib_match and self.pylib_match.match(canonical):
-                return False
+                return None, "is in the stdlib"
 
             # We exclude the coverage code itself, since a little of it will be
             # measured otherwise.
             if self.cover_match and self.cover_match.match(canonical):
-                return False
+                return None, "is part of coverage.py"
 
         # Check the file against the omit pattern.
         if self.omit_match and self.omit_match.match(canonical):
-            return False
+            return None, "is inside an --omit pattern"
 
-        return canonical
+        return canonical, "because we love you"
+
+    def _should_trace(self, filename, frame):
+        """Decide whether to trace execution in `filename`.
 
-    # To log what should_trace returns, change this to "if 1:"
-    if 0:
-        _real_should_trace = _should_trace
-        def _should_trace(self, filename, frame):   # pylint: disable=E0102
-            """A logging decorator around the real _should_trace function."""
-            ret = self._real_should_trace(filename, frame)
-            print("should_trace: %r -> %r" % (filename, ret))
-            return ret
+        Calls `_should_trace_with_reason`, and returns just the decision.
+
+        """
+        canonical, reason = self._should_trace_with_reason(filename, frame)
+        if self.debug.should('trace'):
+            if not canonical:
+                msg = "Not tracing %r: %s" % (filename, reason)
+            else:
+                msg = "Tracing %r" % (filename,)
+            self.debug.write(msg)
+        return canonical
 
     def _warn(self, msg):
         """Use `msg` as a warning."""
@@ -364,6 +390,16 @@ class coverage(object):
         if self.omit:
             self.omit_match = FnmatchMatcher(self.omit)
 
+        # The user may want to debug things, show info if desired.
+        if self.debug.should('config'):
+            self.debug.write("Configuration values:")
+            config_info = sorted(self.config.__dict__.items())
+            self.debug.write_formatted_info(config_info)
+
+        if self.debug.should('sys'):
+            self.debug.write("Debugging info:")
+            self.debug.write_formatted_info(self.sysinfo())
+
         self.collector.start()
         self._started = True
         self._measured = True
@@ -688,11 +724,23 @@ class coverage(object):
             ('executable', sys.executable),
             ('cwd', os.getcwd()),
             ('path', sys.path),
-            ('environment', [
+            ('environment', sorted([
                 ("%s = %s" % (k, v)) for k, v in iitems(os.environ)
                     if re.search(r"^COV|^PY", k)
-                ]),
+                ])),
+            ('command_line', " ".join(getattr(sys, 'argv', ['???']))),
             ]
+        if self.source_match:
+            info.append(('source_match', self.source_match.info()))
+        if self.include_match:
+            info.append(('include_match', self.include_match.info()))
+        if self.omit_match:
+            info.append(('omit_match', self.omit_match.info()))
+        if self.cover_match:
+            info.append(('cover_match', self.cover_match.info()))
+        if self.pylib_match:
+            info.append(('pylib_match', self.pylib_match.info()))
+
         return info
 
 
diff --git a/coverage/data.py b/coverage/data.py
index c86a77f..fb88c5b 100644
--- a/coverage/data.py
+++ b/coverage/data.py
@@ -23,15 +23,18 @@ class CoverageData(object):
 
     """
 
-    def __init__(self, basename=None, collector=None):
+    def __init__(self, basename=None, collector=None, debug=None):
         """Create a CoverageData.
 
         `basename` is the name of the file to use for storing data.
 
         `collector` is a string describing the coverage measurement software.
 
+        `debug` is a `DebugControl` object for writing debug messages.
+
         """
         self.collector = collector or 'unknown'
+        self.debug = debug
 
         self.use_file = True
 
@@ -121,6 +124,9 @@ class CoverageData(object):
         if self.collector:
             data['collector'] = self.collector
 
+        if self.debug and self.debug.should('dataio'):
+            self.debug.write("Writing data to %r" % (filename,))
+
         # Write the pickle to the file.
         fdata = open(filename, 'wb')
         try:
@@ -134,6 +140,8 @@ class CoverageData(object):
 
     def raw_data(self, filename):
         """Return the raw pickled data from `filename`."""
+        if self.debug and self.debug.should('dataio'):
+            self.debug.write("Reading data from %r" % (filename,))
         fdata = open(filename, 'rb')
         try:
             data = pickle.load(fdata)
diff --git a/coverage/debug.py b/coverage/debug.py
new file mode 100644
index 0000000..104f3b1
--- /dev/null
+++ b/coverage/debug.py
@@ -0,0 +1,54 @@
+"""Control of and utilities for debugging."""
+
+import os
+
+
+# When debugging, it can be helpful to force some options, especially when
+# debugging the configuration mechanisms you usually use to control debugging!
+# This is a list of forced debugging options.
+FORCED_DEBUG = []
+
+
+class DebugControl(object):
+    """Control and output for debugging."""
+
+    def __init__(self, options, output):
+        """Configure the options and output file for debugging."""
+        self.options = options
+        self.output = output
+
+    def should(self, option):
+        """Decide whether to output debug information in category `option`."""
+        return (option in self.options or option in FORCED_DEBUG)
+
+    def write(self, msg):
+        """Write a line of debug output."""
+        if self.should('pid'):
+            msg = "pid %5d: %s" % (os.getpid(), msg)
+        self.output.write(msg+"\n")
+        self.output.flush()
+
+    def write_formatted_info(self, info):
+        """Write a sequence of (label,data) pairs nicely."""
+        for line in info_formatter(info):
+            self.write(" %s" % line)
+
+
+def info_formatter(info):
+    """Produce a sequence of formatted lines from info.
+
+    `info` is a sequence of pairs (label, data).  The produced lines are
+    nicely formatted, ready to print.
+
+    """
+    label_len = max([len(l) for l, _d in info])
+    for label, data in info:
+        if data == []:
+            data = "-none-"
+        if isinstance(data, (list, tuple)):
+            prefix = "%*s:" % (label_len, label)
+            for e in data:
+                yield "%*s %s" % (label_len+1, prefix, e)
+                prefix = ""
+        else:
+            yield "%*s: %s" % (label_len, label, data)
diff --git a/coverage/files.py b/coverage/files.py
index 4c55151..8d154c6 100644
--- a/coverage/files.py
+++ b/coverage/files.py
@@ -144,6 +144,10 @@ class TreeMatcher(object):
     def __repr__(self):
         return "<TreeMatcher %r>" % self.dirs
 
+    def info(self):
+        """A list of strings for displaying when dumping state."""
+        return self.dirs
+
     def add(self, directory):
         """Add another directory to the list we match for."""
         self.dirs.append(directory)
@@ -169,6 +173,10 @@ class FnmatchMatcher(object):
     def __repr__(self):
         return "<FnmatchMatcher %r>" % self.pats
 
+    def info(self):
+        """A list of strings for displaying when dumping state."""
+        return self.pats
+
     def match(self, fpath):
         """Does `fpath` match one of our filename patterns?"""
         for pat in self.pats:
diff --git a/coverage/html.py b/coverage/html.py
index ed8920f..aef43be 100644
--- a/coverage/html.py
+++ b/coverage/html.py
@@ -10,10 +10,6 @@ from coverage.report import Reporter
 from coverage.results import Numbers
 from coverage.templite import Templite
 
-# Disable pylint msg W0612, because a bunch of variables look unused, but
-# they're accessed in a Templite context via locals().
-# pylint: disable=W0612
-
 def data_filename(fname):
     """Return the path to a data file of ours."""
     return os.path.join(os.path.split(__file__)[0], fname)
@@ -162,7 +158,6 @@ class HtmlReporter(Reporter):
         nums = analysis.numbers
 
         missing_branch_arcs = analysis.missing_branch_arcs()
-        arcs = self.arcs
 
         # These classes determine which lines are highlighted by default.
         c_run = "run hide_run"
@@ -220,13 +215,17 @@ class HtmlReporter(Reporter):
             })
 
         # Write the HTML page for this file.
-        html_filename = flat_rootname + ".html"
-        html_path = os.path.join(self.directory, html_filename)
-        extra_css = self.extra_css
+        html = spaceless(self.source_tmpl.render({
+            'c_exc': c_exc, 'c_mis': c_mis, 'c_par': c_par, 'c_run': c_run,
+            'arcs': self.arcs, 'extra_css': self.extra_css,
+            'cu': cu, 'nums': nums, 'lines': lines,
+        }))
 
-        html = spaceless(self.source_tmpl.render(locals()))
         if sys.version_info < (3, 0):
             html = html.decode(encoding)
+
+        html_filename = flat_rootname + ".html"
+        html_path = os.path.join(self.directory, html_filename)
         self.write_html(html_path, html)
 
         # Save this file's information for the index file.
@@ -244,13 +243,15 @@ class HtmlReporter(Reporter):
             data("htmlfiles/index.html"), self.template_globals
             )
 
-        files = self.files
-        arcs = self.arcs
+        self.totals = sum([f['nums'] for f in self.files])
 
-        self.totals = totals = sum([f['nums'] for f in files])
-        extra_css = self.extra_css
+        html = index_tmpl.render({
+            'arcs': self.arcs,
+            'extra_css': self.extra_css,
+            'files': self.files,
+            'totals': self.totals,
+        })
 
-        html = index_tmpl.render(locals())
         if sys.version_info < (3, 0):
             html = html.decode("utf-8")
         self.write_html(
diff --git a/coverage/parser.py b/coverage/parser.py
index 8d6a077..2d777a5 100644
--- a/coverage/parser.py
+++ b/coverage/parser.py
@@ -512,11 +512,6 @@ class ByteParser(object):
                     chunk.exits.add(block_stack[-1][1])
                 chunk = None
             if bc.op == OP_END_FINALLY:
-                if block_stack:
-                    # A break that goes through a finally will jump to whatever
-                    # block is on top of the stack.
-                    # print self._block_stack_repr(block_stack)
-                    chunk.exits.add(block_stack[-1][1])
                 # For the finally clause we need to find the closest exception
                 # block, and use its jump target as an exit.
                 for block in reversed(block_stack):
diff --git a/coverage/version.py b/coverage/version.py
index 422fbad..db4bca5 100644
--- a/coverage/version.py
+++ b/coverage/version.py
@@ -1,7 +1,7 @@
 """The version and URL for coverage.py"""
 # This file is exec'ed in setup.py, don't import anything!
 
-__version__ = "3.6.1a0"         # see detailed history in CHANGES.txt
+__version__ = "3.6.1a1"         # see detailed history in CHANGES.txt
 
 __url__ = "http://nedbatchelder.com/code/coverage"
 if max(__version__).isalpha():
diff --git a/igor.py b/igor.py
index e093d49..12ec6c8 100644
--- a/igor.py
+++ b/igor.py
@@ -15,6 +15,10 @@ import sys
 import zipfile
 
 
+# Functions named do_* are executable from the command line: do_blah is run
+# by "python igor.py blah".
+
+
 def do_remove_extension():
     """Remove the compiled C extension, no matter what its name."""
 
@@ -195,6 +199,8 @@ def do_check_eol():
     check_file("setup.py")
     check_file("igor.py")
     check_file("Makefile")
+    check_file(".hgignore")
+    check_file(".travis.yml")
     check_files("doc", ["*.rst"])
     check_files(".", ["*.txt"])
 
@@ -217,7 +223,7 @@ def print_banner(label):
 
 def do_help():
     """List the available commands"""
-    items = globals().items()
+    items = list(globals().items())
     items.sort()
     for name, value in items:
         if name.startswith('do_'):
diff --git a/lab/hack_pyc.py b/lab/hack_pyc.py
index e8992b9..1cdc476 100644
--- a/lab/hack_pyc.py
+++ b/lab/hack_pyc.py
@@ -1,82 +1,82 @@
-""" Wicked hack to get .pyc files to do bytecode tracing instead of

-    line tracing.

-"""

-

-import marshal, new, opcode, sys, types

-

-from lnotab import lnotab_numbers, lnotab_string

-

-class PycFile:

-    def read(self, f):

-        if isinstance(f, basestring):

-            f = open(f, "rb")

-        self.magic = f.read(4)

-        self.modtime = f.read(4)

-        self.code = marshal.load(f)

-    

-    def write(self, f):

-        if isinstance(f, basestring):

-            f = open(f, "wb")

-        f.write(self.magic)

-        f.write(self.modtime)

-        marshal.dump(self.code, f)

-

-    def hack_line_numbers(self):

-        self.code = hack_line_numbers(self.code)

-        

-def hack_line_numbers(code):

-    """ Replace a code object's line number information to claim that every

-        byte of the bytecode is a new source line.  Returns a new code

-        object.  Also recurses to hack the line numbers in nested code objects.

-    """

-    

-    # Create a new lnotab table.  Each opcode is claimed to be at

-    # 1000*lineno + (opcode number within line), so for example, the opcodes on

-    # source line 12 will be given new line numbers 12000, 12001, 12002, etc.

-    old_num = list(lnotab_numbers(code.co_lnotab, code.co_firstlineno))

-    n_bytes = len(code.co_code)

-    new_num = []

-    line = 0

-    opnum_in_line = 0

-    i_byte = 0

-    while i_byte < n_bytes:

-        if old_num and i_byte == old_num[0][0]:

-            line = old_num.pop(0)[1]

-            opnum_in_line = 0

-        new_num.append((i_byte, 100000000 + 1000*line + opnum_in_line))

-        if ord(code.co_code[i_byte]) >= opcode.HAVE_ARGUMENT:

-            i_byte += 3

-        else:

-            i_byte += 1

-        opnum_in_line += 1

-    

-    # new_num is a list of pairs, (byteoff, lineoff).  Turn it into an lnotab.

-    new_firstlineno = new_num[0][1]-1

-    new_lnotab = lnotab_string(new_num, new_firstlineno)

-

-    # Recurse into code constants in this code object.

-    new_consts = []

-    for const in code.co_consts:

-        if type(const) == types.CodeType:

-            new_consts.append(hack_line_numbers(const))

-        else:

-            new_consts.append(const)

-

-    # Create a new code object, just like the old one, except with new

-    # line numbers.

-    new_code = new.code(

-        code.co_argcount, code.co_nlocals, code.co_stacksize, code.co_flags,

-        code.co_code, tuple(new_consts), code.co_names, code.co_varnames,

-        code.co_filename, code.co_name, new_firstlineno, new_lnotab

-        )

-

-    return new_code

-

-def hack_file(f):

-    pyc = PycFile()

-    pyc.read(f)

-    pyc.hack_line_numbers()

-    pyc.write(f)

-

-if __name__ == '__main__':

-    hack_file(sys.argv[1])

+""" Wicked hack to get .pyc files to do bytecode tracing instead of
+    line tracing.
+"""
+
+import marshal, new, opcode, sys, types
+
+from lnotab import lnotab_numbers, lnotab_string
+
+class PycFile:
+    def read(self, f):
+        if isinstance(f, basestring):
+            f = open(f, "rb")
+        self.magic = f.read(4)
+        self.modtime = f.read(4)
+        self.code = marshal.load(f)
+
+    def write(self, f):
+        if isinstance(f, basestring):
+            f = open(f, "wb")
+        f.write(self.magic)
+        f.write(self.modtime)
+        marshal.dump(self.code, f)
+
+    def hack_line_numbers(self):
+        self.code = hack_line_numbers(self.code)
+
+def hack_line_numbers(code):
+    """ Replace a code object's line number information to claim that every
+        byte of the bytecode is a new source line.  Returns a new code
+        object.  Also recurses to hack the line numbers in nested code objects.
+    """
+
+    # Create a new lnotab table.  Each opcode is claimed to be at
+    # 1000*lineno + (opcode number within line), so for example, the opcodes on
+    # source line 12 will be given new line numbers 12000, 12001, 12002, etc.
+    old_num = list(lnotab_numbers(code.co_lnotab, code.co_firstlineno))
+    n_bytes = len(code.co_code)
+    new_num = []
+    line = 0
+    opnum_in_line = 0
+    i_byte = 0
+    while i_byte < n_bytes:
+        if old_num and i_byte == old_num[0][0]:
+            line = old_num.pop(0)[1]
+            opnum_in_line = 0
+        new_num.append((i_byte, 100000000 + 1000*line + opnum_in_line))
+        if ord(code.co_code[i_byte]) >= opcode.HAVE_ARGUMENT:
+            i_byte += 3
+        else:
+            i_byte += 1
+        opnum_in_line += 1
+
+    # new_num is a list of pairs, (byteoff, lineoff).  Turn it into an lnotab.
+    new_firstlineno = new_num[0][1]-1
+    new_lnotab = lnotab_string(new_num, new_firstlineno)
+
+    # Recurse into code constants in this code object.
+    new_consts = []
+    for const in code.co_consts:
+        if type(const) == types.CodeType:
+            new_consts.append(hack_line_numbers(const))
+        else:
+            new_consts.append(const)
+
+    # Create a new code object, just like the old one, except with new
+    # line numbers.
+    new_code = new.code(
+        code.co_argcount, code.co_nlocals, code.co_stacksize, code.co_flags,
+        code.co_code, tuple(new_consts), code.co_names, code.co_varnames,
+        code.co_filename, code.co_name, new_firstlineno, new_lnotab
+        )
+
+    return new_code
+
+def hack_file(f):
+    pyc = PycFile()
+    pyc.read(f)
+    pyc.hack_line_numbers()
+    pyc.write(f)
+
+if __name__ == '__main__':
+    hack_file(sys.argv[1])
diff --git a/lab/sample.py b/lab/sample.py
index cf4f6dc..bb62848 100644
--- a/lab/sample.py
+++ b/lab/sample.py
@@ -1,5 +1,5 @@
-a, b = 1, 0

-if a or b or fn():

-    # Hey

-    a = 3

-d = 4
\ No newline at end of file
+a, b = 1, 0
+if a or b or fn():
+    # Hey
+    a = 3
+d = 4
diff --git a/lab/show_pyc.py b/lab/show_pyc.py
index 7dacc2b..b2cbb34 100644
--- a/lab/show_pyc.py
+++ b/lab/show_pyc.py
@@ -1,70 +1,70 @@
-import dis, marshal, struct, sys, time, types

-

-def show_pyc_file(fname):

-    f = open(fname, "rb")

-    magic = f.read(4)

-    moddate = f.read(4)

-    modtime = time.asctime(time.localtime(struct.unpack('L', moddate)[0]))

-    print "magic %s" % (magic.encode('hex'))

-    print "moddate %s (%s)" % (moddate.encode('hex'), modtime)

-    code = marshal.load(f)

-    show_code(code)

-

-def show_py_file(fname):

-    text = open(fname).read().replace('\r\n', '\n')

-    show_py_text(text, fname=fname)

-

-def show_py_text(text, fname="<string>"):

-    code = compile(text, fname, "exec")

-    show_code(code)

-

-def show_code(code, indent=''):

-    print "%scode" % indent

-    indent += '   '

-    print "%sargcount %d" % (indent, code.co_argcount)

-    print "%snlocals %d" % (indent, code.co_nlocals)

-    print "%sstacksize %d" % (indent, code.co_stacksize)

-    print "%sflags %04x" % (indent, code.co_flags)

-    show_hex("code", code.co_code, indent=indent)

-    dis.disassemble(code)

-    print "%sconsts" % indent

-    for const in code.co_consts:

-        if type(const) == types.CodeType:

-            show_code(const, indent+'   ')

-        else:

-            print "   %s%r" % (indent, const)

-    print "%snames %r" % (indent, code.co_names)

-    print "%svarnames %r" % (indent, code.co_varnames)

-    print "%sfreevars %r" % (indent, code.co_freevars)

-    print "%scellvars %r" % (indent, code.co_cellvars)

-    print "%sfilename %r" % (indent, code.co_filename)

-    print "%sname %r" % (indent, code.co_name)

-    print "%sfirstlineno %d" % (indent, code.co_firstlineno)

-    show_hex("lnotab", code.co_lnotab, indent=indent)

-    

-def show_hex(label, h, indent):

-    h = h.encode('hex')

-    if len(h) < 60:

-        print "%s%s %s" % (indent, label, h)

-    else:

-        print "%s%s" % (indent, label)

-        for i in range(0, len(h), 60):

-            print "%s   %s" % (indent, h[i:i+60])

-

-def show_file(fname):

-    if fname.endswith('pyc'):

-        show_pyc_file(fname)

-    elif fname.endswith('py'):

-        show_py_file(fname)

-    else:

-        print "Odd file:", fname

-

-def main(args):

-    if args[0] == '-c':

-        show_py_text(" ".join(args[1:]).replace(";", "\n"))

-    else:

-        for a in args:

-            show_file(a)

-

-if __name__ == '__main__':

-    main(sys.argv[1:])

+import dis, marshal, struct, sys, time, types
+
+def show_pyc_file(fname):
+    f = open(fname, "rb")
+    magic = f.read(4)
+    moddate = f.read(4)
+    modtime = time.asctime(time.localtime(struct.unpack('L', moddate)[0]))
+    print "magic %s" % (magic.encode('hex'))
+    print "moddate %s (%s)" % (moddate.encode('hex'), modtime)
+    code = marshal.load(f)
+    show_code(code)
+
+def show_py_file(fname):
+    text = open(fname).read().replace('\r\n', '\n')
+    show_py_text(text, fname=fname)
+
+def show_py_text(text, fname="<string>"):
+    code = compile(text, fname, "exec")
+    show_code(code)
+
+def show_code(code, indent=''):
+    print "%scode" % indent
+    indent += '   '
+    print "%sargcount %d" % (indent, code.co_argcount)
+    print "%snlocals %d" % (indent, code.co_nlocals)
+    print "%sstacksize %d" % (indent, code.co_stacksize)
+    print "%sflags %04x" % (indent, code.co_flags)
+    show_hex("code", code.co_code, indent=indent)
+    dis.disassemble(code)
+    print "%sconsts" % indent
+    for const in code.co_consts:
+        if type(const) == types.CodeType:
+            show_code(const, indent+'   ')
+        else:
+            print "   %s%r" % (indent, const)
+    print "%snames %r" % (indent, code.co_names)
+    print "%svarnames %r" % (indent, code.co_varnames)
+    print "%sfreevars %r" % (indent, code.co_freevars)
+    print "%scellvars %r" % (indent, code.co_cellvars)
+    print "%sfilename %r" % (indent, code.co_filename)
+    print "%sname %r" % (indent, code.co_name)
+    print "%sfirstlineno %d" % (indent, code.co_firstlineno)
+    show_hex("lnotab", code.co_lnotab, indent=indent)
+
+def show_hex(label, h, indent):
+    h = h.encode('hex')
+    if len(h) < 60:
+        print "%s%s %s" % (indent, label, h)
+    else:
+        print "%s%s" % (indent, label)
+        for i in range(0, len(h), 60):
+            print "%s   %s" % (indent, h[i:i+60])
+
+def show_file(fname):
+    if fname.endswith('pyc'):
+        show_pyc_file(fname)
+    elif fname.endswith('py'):
+        show_py_file(fname)
+    else:
+        print "Odd file:", fname
+
+def main(args):
+    if args[0] == '-c':
+        show_py_text(" ".join(args[1:]).replace(";", "\n"))
+    else:
+        for a in args:
+            show_file(a)
+
+if __name__ == '__main__':
+    main(sys.argv[1:])
diff --git a/lab/trace_sample.py b/lab/trace_sample.py
index 9fa3724..3f81919 100644
--- a/lab/trace_sample.py
+++ b/lab/trace_sample.py
@@ -1,57 +1,57 @@
-import os, sys

-

-global nest

-nest = 0

-

-def trace(frame, event, arg):

-    #if event == 'line':

-    global nest

-    

-    print "%s%s %s %d" % (

-        "   " * nest,

-        event,

-        os.path.basename(frame.f_code.co_filename),

-        frame.f_lineno,

-        )

-    

-    if event == 'call':

-        nest += 1

-    if event == 'return':

-        nest -= 1

-        

-    return trace

-

-def trace2(frame, event, arg):

-    #if event == 'line':

-    global nest

-    

-    print "2: %s%s %s %d" % (

-        "   " * nest,

-        event,

-        os.path.basename(frame.f_code.co_filename),

-        frame.f_lineno,

-        )

-    

-    if event == 'call':

-        nest += 1

-    if event == 'return':

-        nest -= 1

-        

-    return trace2

-

-sys.settrace(trace)

-

-def bar():

-    print "nar"

-

-a = 26

-def foo(n):

-    a = 28

-    sys.settrace(sys.gettrace())

-    bar()

-    a = 30  

-    return 2*n

-

-print foo(a)

-#import sample

-#import littleclass

+import os, sys
+
+global nest
+nest = 0
+
+def trace(frame, event, arg):
+    #if event == 'line':
+    global nest
+
+    print "%s%s %s %d" % (
+        "   " * nest,
+        event,
+        os.path.basename(frame.f_code.co_filename),
+        frame.f_lineno,
+        )
+
+    if event == 'call':
+        nest += 1
+    if event == 'return':
+        nest -= 1
+
+    return trace
+
+def trace2(frame, event, arg):
+    #if event == 'line':
+    global nest
+
+    print "2: %s%s %s %d" % (
+        "   " * nest,
+        event,
+        os.path.basename(frame.f_code.co_filename),
+        frame.f_lineno,
+        )
+
+    if event == 'call':
+        nest += 1
+    if event == 'return':
+        nest -= 1
+
+    return trace2
+
+sys.settrace(trace)
+
+def bar():
+    print "nar"
+
+a = 26
+def foo(n):
+    a = 28
+    sys.settrace(sys.gettrace())
+    bar()
+    a = 30
+    return 2*n
+
+print foo(a)
+#import sample
+#import littleclass
diff --git a/tests/coveragetest.py b/tests/coveragetest.py
index 5613fa6..5060b53 100644
--- a/tests/coveragetest.py
+++ b/tests/coveragetest.py
@@ -36,8 +36,12 @@ OK, ERR = 0, 1
 class CoverageTest(TestCase):
     """A base class for Coverage test cases."""
 
+    # Our own setting: most CoverageTests run in their own temp directory.
     run_in_temp_dir = True
 
+    # Standard unittest setting: show me diffs even if they are very long.
+    maxDiff = None
+
     def setUp(self):
         super(CoverageTest, self).setUp()
 
@@ -61,8 +65,11 @@ class CoverageTest(TestCase):
             self.old_dir = os.getcwd()
             os.chdir(self.temp_dir)
 
-            # Modules should be importable from this temp directory.
-            sys.path.insert(0, '')
+            # Modules should be importable from this temp directory.  We don't
+            # use '' because we make lots of different temp directories and
+            # nose's caching importer can get confused.  The full path prevents
+            # problems.
+            sys.path.insert(0, os.getcwd())
 
             # Keep a counter to make every call to check_coverage unique.
             self.n = 0
diff --git a/tests/test_arcs.py b/tests/test_arcs.py
index f3c5fc3..6268e28 100644
--- a/tests/test_arcs.py
+++ b/tests/test_arcs.py
@@ -141,7 +141,7 @@ class SimpleArcTest(CoverageTest):
             )
 
     if 0:   # expected failure
-        def test_lambdas_are_confusing_bug_90(self):
+        def test_unused_lambdas_are_confusing_bug_90(self):
             self.check_coverage("""\
                 a = 1
                 fn = lambda x: x
@@ -172,9 +172,9 @@ if sys.version_info >= (2, 6):
             self.check_coverage("""\
                 for i in range(2):
                     with open("test", "w") as f:
-                        print 3
-                    print 4
-                print 5
+                        print(3)
+                    print(4)
+                print(5)
                 """,
                 arcz=".1 12 23 34 41 15 5."
                 )
@@ -456,8 +456,8 @@ class ExceptionArcTest(CoverageTest):
                 d = 12                              # C
             assert a == 5 and c == 10 and d == 12   # D
             """,
-            arcz=".1 12 23 34 3D 45 56 67 68 8A A3 AB AD BC CD D.",
-            arcz_missing="3D AD", arcz_unpredicted="7A")
+            arcz=".1 12 23 34 3D 45 56 67 68 8A A3 AB BC CD D.",
+            arcz_missing="3D", arcz_unpredicted="7A")
         self.check_coverage("""\
             a, c, d, i = 1, 1, 1, 99
             try:
@@ -473,8 +473,8 @@ class ExceptionArcTest(CoverageTest):
                 d = 12                              # C
             assert a == 8 and c == 10 and d == 1    # D
             """,
-            arcz=".1 12 23 34 3D 45 56 67 68 8A A3 AB AD BC CD D.",
-            arcz_missing="67 AB AD BC CD", arcz_unpredicted="")
+            arcz=".1 12 23 34 3D 45 56 67 68 8A A3 AB BC CD D.",
+            arcz_missing="67 AB BC CD", arcz_unpredicted="")
 
 
     def test_break_in_finally(self):
@@ -493,22 +493,45 @@ class ExceptionArcTest(CoverageTest):
                 d = 12                              # C
             assert a == 5 and c == 10 and d == 1    # D
             """,
-            arcz=".1 12 23 34 3D 45 56 67 68 7A 8A A3 AB AD BC CD D.",
-            arcz_missing="3D AB BC CD", arcz_unpredicted="")
+            arcz=".1 12 23 34 3D 45 56 67 68 7A 8A A3 AB BC CD D.",
+            arcz_missing="3D AB BC CD", arcz_unpredicted="AD")
 
-    if 0:   # expected failure
-        def test_finally_in_loop_bug_92(self):
+    def test_finally_in_loop_bug_92(self):
+        self.check_coverage("""\
+            for i in range(5):
+                try:
+                    j = 3
+                finally:
+                    f = 5
+                g = 6
+            h = 7
+            """,
+            arcz=".1 12 23 35 56 61 17 7.",
+            arcz_missing="", arcz_unpredicted="")
+
+    # Run this test only on 2.6 and 2.7 for now.  I hope to fix it on Py3
+    # eventually...
+    if (2, 6) <= sys.version_info < (3,):
+        # "except Exception as e" is crucial here.
+        def test_bug_212(self):
             self.check_coverage("""\
-                for i in range(5):
+                def b(exc):
                     try:
-                        j = 3
-                    finally:
-                        f = 5
-                    g = 6
-                h = 7
+                        while 1:
+                            raise Exception(exc)    # 4
+                    except Exception as e:
+                        if exc != 'expected':
+                            raise
+                        q = 8
+
+                b('expected')
+                try:
+                    b('unexpected')     # C
+                except:
+                    pass
                 """,
-                arcz=".1 12 23 35 56 61 17 7.",
-                arcz_missing="", arcz_unpredicted="")
+                arcz=".1 .2 1A 23 34 56 67 68 8. AB BC C. DE E.",
+                arcz_missing="C.", arcz_unpredicted="45 7. CD")
 
     if sys.version_info >= (2, 5):
         # Try-except-finally was new in 2.5
diff --git a/tests/test_cmdline.py b/tests/test_cmdline.py
index 6b11b3e..493ce18 100644
--- a/tests/test_cmdline.py
+++ b/tests/test_cmdline.py
@@ -15,7 +15,7 @@ class CmdLineTest(CoverageTest):
     run_in_temp_dir = False
 
     INIT_LOAD = """\
-        .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None)
+        .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None, debug=None)
         .load()\n"""
 
     def model_object(self):
@@ -104,7 +104,7 @@ class ClassicCmdLineTest(CmdLineTest):
     def test_erase(self):
         # coverage -e
         self.cmd_executes("-e", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None)
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None, debug=None)
             .erase()
             """)
         self.cmd_executes_same("-e", "--erase")
@@ -114,7 +114,7 @@ class ClassicCmdLineTest(CmdLineTest):
 
         # -x calls coverage.load first.
         self.cmd_executes("-x foo.py", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None)
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None, debug=None)
             .load()
             .start()
             .run_python_file('foo.py', ['foo.py'])
@@ -123,7 +123,7 @@ class ClassicCmdLineTest(CmdLineTest):
             """)
         # -e -x calls coverage.erase first.
         self.cmd_executes("-e -x foo.py", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None)
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None, debug=None)
             .erase()
             .start()
             .run_python_file('foo.py', ['foo.py'])
@@ -132,7 +132,7 @@ class ClassicCmdLineTest(CmdLineTest):
             """)
         # --timid sets a flag, and program arguments get passed through.
         self.cmd_executes("-x --timid foo.py abc 123", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=True, branch=None, config_file=True, source=None, include=None, omit=None)
+            .coverage(cover_pylib=None, data_suffix=None, timid=True, branch=None, config_file=True, source=None, include=None, omit=None, debug=None)
             .load()
             .start()
             .run_python_file('foo.py', ['foo.py', 'abc', '123'])
@@ -141,7 +141,7 @@ class ClassicCmdLineTest(CmdLineTest):
             """)
         # -L sets a flag, and flags for the program don't confuse us.
         self.cmd_executes("-x -p -L foo.py -a -b", """\
-            .coverage(cover_pylib=True, data_suffix=True, timid=None, branch=None, config_file=True, source=None, include=None, omit=None)
+            .coverage(cover_pylib=True, data_suffix=True, timid=None, branch=None, config_file=True, source=None, include=None, omit=None, debug=None)
             .load()
             .start()
             .run_python_file('foo.py', ['foo.py', '-a', '-b'])
@@ -158,7 +158,7 @@ class ClassicCmdLineTest(CmdLineTest):
     def test_combine(self):
         # coverage -c
         self.cmd_executes("-c", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None)
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None, debug=None)
             .load()
             .combine()
             .save()
@@ -180,13 +180,13 @@ class ClassicCmdLineTest(CmdLineTest):
                     show_missing=True)
             """)
         self.cmd_executes("-r -o fooey", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey"])
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey"], debug=None)
             .load()
             .report(ignore_errors=None, omit=["fooey"], include=None,
                     morfs=[], show_missing=None)
             """)
         self.cmd_executes("-r -o fooey,booey", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey", "booey"])
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey", "booey"], debug=None)
             .load()
             .report(ignore_errors=None, omit=["fooey", "booey"], include=None,
                     morfs=[], show_missing=None)
@@ -225,13 +225,13 @@ class ClassicCmdLineTest(CmdLineTest):
                     omit=None, include=None, morfs=[])
             """)
         self.cmd_executes("-a -o fooey", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey"])
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey"], debug=None)
             .load()
             .annotate(directory=None, ignore_errors=None,
                     omit=["fooey"], include=None, morfs=[])
             """)
         self.cmd_executes("-a -o fooey,booey", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey", "booey"])
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey", "booey"], debug=None)
             .load()
             .annotate(directory=None, ignore_errors=None,
                     omit=["fooey", "booey"], include=None, morfs=[])
@@ -270,13 +270,13 @@ class ClassicCmdLineTest(CmdLineTest):
                     omit=None, include=None, morfs=[])
             """)
         self.cmd_executes("-b -o fooey", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey"])
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey"], debug=None)
             .load()
             .html_report(directory=None, ignore_errors=None, title=None,
                     omit=["fooey"], include=None, morfs=[])
             """)
         self.cmd_executes("-b -o fooey,booey", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey", "booey"])
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey", "booey"], debug=None)
             .load()
             .html_report(directory=None, ignore_errors=None, title=None,
                     omit=["fooey", "booey"], include=None, morfs=[])
@@ -481,7 +481,7 @@ class NewCmdLineTest(CmdLineTest):
         self.cmd_executes_same("run --timid f.py", "-e -x --timid f.py")
         self.cmd_executes_same("run", "-x")
         self.cmd_executes("run --branch foo.py", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=True, config_file=True, source=None, include=None, omit=None)
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=True, config_file=True, source=None, include=None, omit=None, debug=None)
             .erase()
             .start()
             .run_python_file('foo.py', ['foo.py'])
@@ -489,7 +489,7 @@ class NewCmdLineTest(CmdLineTest):
             .save()
             """)
         self.cmd_executes("run --rcfile=myrc.rc foo.py", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file="myrc.rc", source=None, include=None, omit=None)
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file="myrc.rc", source=None, include=None, omit=None, debug=None)
             .erase()
             .start()
             .run_python_file('foo.py', ['foo.py'])
@@ -497,7 +497,7 @@ class NewCmdLineTest(CmdLineTest):
             .save()
             """)
         self.cmd_executes("run --include=pre1,pre2 foo.py", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=["pre1", "pre2"], omit=None)
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=["pre1", "pre2"], omit=None, debug=None)
             .erase()
             .start()
             .run_python_file('foo.py', ['foo.py'])
@@ -505,7 +505,7 @@ class NewCmdLineTest(CmdLineTest):
             .save()
             """)
         self.cmd_executes("run --omit=opre1,opre2 foo.py", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["opre1", "opre2"])
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["opre1", "opre2"], debug=None)
             .erase()
             .start()
             .run_python_file('foo.py', ['foo.py'])
@@ -517,7 +517,9 @@ class NewCmdLineTest(CmdLineTest):
             .coverage(cover_pylib=None, data_suffix=None, timid=None,
                 branch=None, config_file=True, source=None,
                 include=["pre1", "pre2"],
-                omit=["opre1", "opre2"])
+                omit=["opre1", "opre2"],
+                debug=None,
+            )
             .erase()
             .start()
             .run_python_file('foo.py', ['foo.py'])
@@ -529,7 +531,37 @@ class NewCmdLineTest(CmdLineTest):
             .coverage(cover_pylib=None, data_suffix=None, timid=None,
                 branch=None, config_file=True,
                 source=["quux", "hi.there", "/home/bar"], include=None,
-                omit=None)
+                omit=None,
+                debug=None,
+            )
+            .erase()
+            .start()
+            .run_python_file('foo.py', ['foo.py'])
+            .stop()
+            .save()
+            """)
+
+    def test_run_debug(self):
+        self.cmd_executes("run --debug=opt1 foo.py", """\
+            .coverage(cover_pylib=None, data_suffix=None, timid=None,
+                branch=None, config_file=True,
+                source=None, include=None,
+                omit=None,
+                debug=["opt1"],
+            )
+            .erase()
+            .start()
+            .run_python_file('foo.py', ['foo.py'])
+            .stop()
+            .save()
+            """)
+        self.cmd_executes("run --debug=opt1,opt2 foo.py", """\
+            .coverage(cover_pylib=None, data_suffix=None, timid=None,
+                branch=None, config_file=True,
+                source=None, include=None,
+                omit=None,
+                debug=["opt1","opt2"],
+            )
             .erase()
             .start()
             .run_python_file('foo.py', ['foo.py'])
@@ -539,7 +571,7 @@ class NewCmdLineTest(CmdLineTest):
 
     def test_run_module(self):
         self.cmd_executes("run -m mymodule", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None)
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None, debug=None)
             .erase()
             .start()
             .run_python_module('mymodule', ['mymodule'])
@@ -547,7 +579,7 @@ class NewCmdLineTest(CmdLineTest):
             .save()
             """)
         self.cmd_executes("run -m mymodule -qq arg1 arg2", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None)
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=None, debug=None)
             .erase()
             .start()
             .run_python_module('mymodule', ['mymodule', '-qq', 'arg1', 'arg2'])
@@ -555,7 +587,7 @@ class NewCmdLineTest(CmdLineTest):
             .save()
             """)
         self.cmd_executes("run --branch -m mymodule", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=True, config_file=True, source=None, include=None, omit=None)
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=True, config_file=True, source=None, include=None, omit=None, debug=None)
             .erase()
             .start()
             .run_python_module('mymodule', ['mymodule'])
@@ -583,13 +615,13 @@ class NewCmdLineTest(CmdLineTest):
                     outfile="-")
             """)
         self.cmd_executes("xml --omit fooey", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey"])
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey"], debug=None)
             .load()
             .xml_report(ignore_errors=None, omit=["fooey"], include=None, morfs=[],
                     outfile=None)
             """)
         self.cmd_executes("xml --omit fooey,booey", """\
-            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey", "booey"])
+            .coverage(cover_pylib=None, data_suffix=None, timid=None, branch=None, config_file=True, source=None, include=None, omit=["fooey", "booey"], debug=None)
             .load()
             .xml_report(ignore_errors=None, omit=["fooey", "booey"], include=None,
                     morfs=[], outfile=None)
diff --git a/tests/test_collector.py b/tests/test_collector.py
new file mode 100644
index 0000000..af3814f
--- /dev/null
+++ b/tests/test_collector.py
@@ -0,0 +1,57 @@
+"""Tests of coverage/collector.py and other collectors."""
+
+import re
+
+import coverage
+from coverage.backward import StringIO
+
+from tests.coveragetest import CoverageTest
+
+
+class CollectorTest(CoverageTest):
+    """Test specific aspects of the collection process."""
+
+    def test_should_trace_cache(self):
+        # The tracers should only invoke should_trace once for each file name.
+        # TODO: Might be better to do this with a mocked _should_trace,
+        # rather than by examining debug output.
+
+        # Make some files that invoke each other.
+        self.make_file("f1.py", """\
+            def f1(x, f):
+                return f(x)
+            """)
+
+        self.make_file("f2.py", """\
+            import f1
+
+            def func(x):
+                return f1.f1(x, otherfunc)
+
+            def otherfunc(x):
+                return x*x
+
+            for i in range(10):
+                func(i)
+            """)
+
+        # Trace one file, but not the other, and get the debug output.
+        debug_out = StringIO()
+        cov = coverage.coverage(
+            include=["f1.py"], debug=['trace'], debug_file=debug_out
+            )
+
+        # Import the python file, executing it.
+        self.start_import_stop(cov, "f2")
+
+        # Grab all the filenames mentioned in debug output, there should be no
+        # duplicates.
+        trace_lines = [
+            l for l in debug_out.getvalue().splitlines()
+            if l.startswith("Tracing ") or l.startswith("Not tracing ")
+        ]
+        filenames = [re.search(r"'[^']+'", l).group() for l in trace_lines]
+        self.assertEqual(len(filenames), len(set(filenames)))
+
+        # Double-check that the tracing messages are in there somewhere.
+        self.assertGreater(len(filenames), 5)
diff --git a/tests/test_debug.py b/tests/test_debug.py
new file mode 100644
index 0000000..0132c1c
--- /dev/null
+++ b/tests/test_debug.py
@@ -0,0 +1,113 @@
+"""Tests of coverage/debug.py"""
+
+import os
+import re
+
+import coverage
+from coverage.backward import StringIO
+from coverage.debug import info_formatter
+from tests.coveragetest import CoverageTest
+
+
+class InfoFormatterTest(CoverageTest):
+    """Tests of misc.info_formatter."""
+
+    def test_info_formatter(self):
+        lines = list(info_formatter([
+            ('x', 'hello there'),
+            ('very long label', ['one element']),
+            ('regular', ['abc', 'def', 'ghi', 'jkl']),
+            ('nothing', []),
+        ]))
+        self.assertEqual(lines, [
+            '              x: hello there',
+            'very long label: one element',
+            '        regular: abc',
+            '                 def',
+            '                 ghi',
+            '                 jkl',
+            '        nothing: -none-',
+        ])
+
+
+class DebugTraceTest(CoverageTest):
+    """Tests of debug output."""
+
+    def f1_debug_output(self, debug):
+        """Runs some code with `debug` option, returns the debug output."""
+        # Make code to run.
+        self.make_file("f1.py", """\
+            def f1(x):
+                return x+1
+
+            for i in range(5):
+                f1(i)
+            """)
+
+        debug_out = StringIO()
+        cov = coverage.coverage(debug=debug, debug_file=debug_out)
+        self.start_import_stop(cov, "f1")
+
+        out_lines = debug_out.getvalue().splitlines()
+        return out_lines
+
+    def test_debug_no_trace(self):
+        out_lines = self.f1_debug_output([])
+
+        # We should have no output at all.
+        self.assertFalse(out_lines)
+
+    def test_debug_trace(self):
+        out_lines = self.f1_debug_output(["trace"])
+
+        # We should have a line like "Tracing 'f1.py'"
+        self.assertIn("Tracing 'f1.py'", out_lines)
+
+        # We should lines like "Not tracing 'collector.py'..."
+        coverage_lines = lines_matching(
+            out_lines,
+            r"^Not tracing .*: is part of coverage.py$"
+            )
+        self.assertTrue(coverage_lines)
+
+    def test_debug_trace_pid(self):
+        out_lines = self.f1_debug_output(["trace", "pid"])
+
+        # Now our lines are always prefixed with the process id.
+        pid_prefix = "^pid %5d: " % os.getpid()
+        pid_lines = lines_matching(out_lines, pid_prefix)
+        self.assertEqual(pid_lines, out_lines)
+
+        # We still have some tracing, and some not tracing.
+        self.assertTrue(lines_matching(out_lines, pid_prefix + "Tracing "))
+        self.assertTrue(lines_matching(out_lines, pid_prefix + "Not tracing "))
+
+    def test_debug_config(self):
+        out_lines = self.f1_debug_output(["config"])
+
+        labels = """
+            attempted_config_files branch config_files cover_pylib data_file
+            debug exclude_list extra_css html_dir html_title ignore_errors
+            include omit parallel partial_always_list partial_list paths
+            precision show_missing source timid xml_output
+            """.split()
+        for label in labels:
+            label_pat = r"^\s*%s: " % label
+            self.assertEqual(len(lines_matching(out_lines, label_pat)), 1)
+
+    def test_debug_sys(self):
+        out_lines = self.f1_debug_output(["sys"])
+
+        labels = """
+            version coverage cover_dir pylib_dirs tracer config_files
+            configs_read data_path python platform implementation executable
+            cwd path environment command_line cover_match pylib_match
+            """.split()
+        for label in labels:
+            label_pat = r"^\s*%s: " % label
+            self.assertEqual(len(lines_matching(out_lines, label_pat)), 1)
+
+
+def lines_matching(lines, pat):
+    """Gives the list of lines from `lines` that match `pat`."""
+    return [l for l in lines if re.search(pat, l)]
diff --git a/tests/test_farm.py b/tests/test_farm.py
index e514e66..fee2806 100644
--- a/tests/test_farm.py
+++ b/tests/test_farm.py
@@ -195,9 +195,9 @@ class FarmTestCase(object):
         """Compare files matching `file_pattern` in `dir1` and `dir2`.
 
         `dir2` is interpreted as a prefix, with Python version numbers appended
-        to find the actual directory to compare with. "foo" will compare against
-        "foo_v241", "foo_v24", "foo_v2", or "foo", depending on which directory
-        is found first.
+        to find the actual directory to compare with. "foo" will compare
+        against "foo_v241", "foo_v24", "foo_v2", or "foo", depending on which
+        directory is found first.
 
         `size_within` is a percentage delta for the file sizes.  If non-zero,
         then the file contents are not compared (since they are expected to
diff --git a/tests/test_files.py b/tests/test_files.py
index 509c23b..eeb2264 100644
--- a/tests/test_files.py
+++ b/tests/test_files.py
@@ -58,16 +58,19 @@ class MatcherTest(CoverageTest):
         file4 = self.make_file("sub3/file4.py")
         file5 = self.make_file("sub3/file5.c")
         fl = FileLocator()
-        tm = TreeMatcher([
+        trees = [
             fl.canonical_filename("sub"),
             fl.canonical_filename(file4),
-            ])
+            ]
+        tm = TreeMatcher(trees)
         self.assertTrue(tm.match(fl.canonical_filename(file1)))
         self.assertTrue(tm.match(fl.canonical_filename(file2)))
         self.assertFalse(tm.match(fl.canonical_filename(file3)))
         self.assertTrue(tm.match(fl.canonical_filename(file4)))
         self.assertFalse(tm.match(fl.canonical_filename(file5)))
 
+        self.assertEqual(tm.info(), trees)
+
     def test_fnmatch_matcher(self):
         file1 = self.make_file("sub/file1.py")
         file2 = self.make_file("sub/file2.c")
@@ -82,6 +85,8 @@ class MatcherTest(CoverageTest):
         self.assertTrue(fnm.match(fl.canonical_filename(file4)))
         self.assertFalse(fnm.match(fl.canonical_filename(file5)))
 
+        self.assertEqual(fnm.info(), ["*.py", "*/sub2/*"])
+
 
 class PathAliasesTest(CoverageTest):
     """Tests for coverage/files.py:PathAliases"""
diff --git a/tests/test_html.py b/tests/test_html.py
index 40852ac..c004303 100644
--- a/tests/test_html.py
+++ b/tests/test_html.py
@@ -52,8 +52,6 @@ class HtmlDeltaTest(HtmlTestHelpers, CoverageTest):
         # so grab it here to restore it later.
         self.real_coverage_version = coverage.__version__
 
-        self.maxDiff = None
-
     def tearDown(self):
         coverage.__version__ = self.real_coverage_version
         super(HtmlDeltaTest, self).tearDown()
@@ -291,6 +289,7 @@ class HtmlTest(CoverageTest):
         os.remove("sub/another.py")
 
         missing_file = os.path.join(self.temp_dir, "sub", "another.py")
+        missing_file = os.path.realpath(missing_file)
         self.assertRaisesRegexp(NoSource,
             "(?i)No source for code: '%s'" % re.escape(missing_file),
             cov.html_report
diff --git a/tests/test_misc.py b/tests/test_misc.py
index e7fa436..50ddb17 100644
--- a/tests/test_misc.py
+++ b/tests/test_misc.py
@@ -1,4 +1,5 @@
 """Tests of miscellaneous stuff."""
+
 import sys
 
 from coverage.misc import Hasher, file_be_gone
diff --git a/tests/test_process.py b/tests/test_process.py
index 8554eb5..97e2f82 100644
--- a/tests/test_process.py
+++ b/tests/test_process.py
@@ -583,7 +583,7 @@ class ProcessStartupTest(CoverageTest):
                         pass
                 finally:
                     pth.close()
-        else:                                       # pragma: not covered
+        else:                                           # pragma: not covered
             raise Exception("Couldn't find a place for the .pth file")
 
     def tearDown(self):
@@ -615,7 +615,9 @@ class ProcessStartupTest(CoverageTest):
         import main             # pylint: disable=F0401,W0612
 
         self.assertEqual(open("out.txt").read(), "Hello, world!\n")
+
         # Read the data from .coverage
+        self.assert_exists(".mycovdata")
         data = coverage.CoverageData()
         data.read_file(".mycovdata")
         self.assertEqual(data.summary()['sub.py'], 3)