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

third_party/coverage-3.7.1/coverage/misc.py

 """Miscellaneous stuff for Coverage."""
 
 import errno
 import inspect
 import os
 import sys
 
 from coverage.backward import md5, sorted       # pylint: disable=W0622
 from coverage.backward import string_class, to_bytes
 
@@ skipping 20 matching lines @@
     even if there are gaps between statements.
 
     For example, if `statements` is [1,2,3,4,5,10,11,12,13,14] and
     `lines` is [1,2,5,10,11,13,14] then the result will be "1-2, 5-11, 13-14".
 
     """
     pairs = []
     i = 0
     j = 0
     start = None
+    statements = sorted(statements)
+    lines = sorted(lines)
     while i < len(statements) and j < len(lines):
         if statements[i] == lines[j]:
             if start == None:
                 start = lines[j]
             end = lines[j]
             j += 1
         elif start:
             pairs.append((start, end))
             start = None
         i += 1
@@ skipping 28 matching lines @@
     """Return bool(b), but preserve None."""
     if b is None:
         return None
     else:
         return bool(b)
 
 
 def join_regex(regexes):
     """Combine a list of regexes into one that matches any of them."""
     if len(regexes) > 1:
-        return "(" + ")|(".join(regexes) + ")"
+        return "|".join(["(%s)" % r for r in regexes])
     elif regexes:
         return regexes[0]
     else:
         return ""
 
 
 def file_be_gone(path):
     """Remove a file, and don't get annoyed if it doesn't exist."""
     try:
         os.remove(path)
     except OSError:
         _, e, _ = sys.exc_info()
         if e.errno != errno.ENOENT:
             raise
 
 
 class Hasher(object):
     """Hashes Python data into md5."""
     def __init__(self):
         self.md5 = md5()
 
     def update(self, v):
         """Add `v` to the hash, recursively if needed."""
         self.md5.update(to_bytes(str(type(v))))
         if isinstance(v, string_class):
             self.md5.update(to_bytes(v))
+        elif v is None:
+            pass
         elif isinstance(v, (int, float)):
-            self.update(str(v))
+            self.md5.update(to_bytes(str(v)))
         elif isinstance(v, (tuple, list)):
             for e in v:
                 self.update(e)
         elif isinstance(v, dict):
             keys = v.keys()
             for k in sorted(keys):
                 self.update(k)
                 self.update(v[k])
         else:
             for k in dir(v):
@@ skipping 11 matching lines @@
 
 
 class CoverageException(Exception):
     """An exception specific to Coverage."""
     pass
 
 class NoSource(CoverageException):
     """We couldn't find the source for a module."""
     pass
 
+class NoCode(NoSource):
+    """We couldn't find any code at all."""
+    pass
+
 class NotPython(CoverageException):
     """A source file turned out not to be parsable Python."""
     pass
 
 class ExceptionDuringRun(CoverageException):
     """An exception happened while running customer code.
 
     Construct it with three arguments, the values from `sys.exc_info`.
 
     """
     pass