--- a/python/mozbuild/mozbuild/base.py
+++ b/python/mozbuild/mozbuild/base.py
@@ -6,17 +6,22 @@ from __future__ import absolute_import, 
 
 import json
 import logging
 import mozpack.path as mozpath
 import multiprocessing
 import os
 import subprocess
 import sys
-import which
+
+try:
+    from shutil import which
+except ImportError:
+    # shutil.which is not available in Python 2.7
+    import which
 
 from mach.mixin.process import ProcessExecutionMixin
 from mozversioncontrol import (
     get_repository_from_build_config,
     get_repository_object,
     InvalidRepoPath,
 )
 

--- a/testing/mozbase/mozlog/mozlog/commandline.py
+++ b/testing/mozbase/mozlog/mozlog/commandline.py
@@ -259,17 +259,17 @@ def setup_logging(logger, args, defaults
         #               or ['valgrind']
         if parts[0] == 'log' and values is not None:
             if len(parts) == 1 or parts[1] not in log_formatters:
                 continue
             if len(parts) == 2:
                 _, formatter = parts
                 for value in values:
                     found = True
-                    if isinstance(value, six.string_types):
+                    if isinstance(value, basestring):
                         value = log_file(value)
                     if value == sys.stdout:
                         found_stdout_logger = True
                     formatters[formatter].append(value)
             if len(parts) == 3:
                 _, formatter, opt = parts
                 if formatter not in formatter_options:
                     formatter_options[formatter] = default_formatter_options(formatter,

--- a/testing/mozbase/mozlog/mozlog/formatters/machformatter.py
+++ b/testing/mozbase/mozlog/mozlog/formatters/machformatter.py
@@ -57,17 +57,17 @@ class MachFormatter(base.BaseFormatter):
 
     def _get_test_id(self, data):
         test_id = data.get("test")
         if isinstance(test_id, list):
             test_id = tuple(test_id)
         return test_id
 
     def _get_file_name(self, test_id):
-        if isinstance(test_id, (str, six.text_type)):
+        if isinstance(test_id, (str, unicode)):
             return test_id
 
         if isinstance(test_id, tuple):
             return "".join(test_id)
 
         assert False, "unexpected test_id"
 
     def suite_start(self, data):

--- a/testing/mozbase/mozlog/mozlog/formatters/tbplformatter.py
+++ b/testing/mozbase/mozlog/mozlog/formatters/tbplformatter.py
@@ -253,17 +253,17 @@ class TbplFormatter(BaseFormatter):
 
     def suite_end(self, data):
         start_time = self.suite_start_time
         time = int((data["time"] - start_time) / 1000)
 
         return "SUITE-END | took %is\n" % time
 
     def test_id(self, test_id):
-        if isinstance(test_id, (str, six.text_type)):
+        if isinstance(test_id, (str, unicode)):
             return test_id
         else:
             return tuple(test_id)
 
     @output_subtests
     def valgrind_error(self, data):
         rv = "TEST-UNEXPECTED-VALGRIND-ERROR | " + data['primary'] + "\n"
         for line in data['secondary']:

--- a/testing/mozbase/mozlog/mozlog/formatters/xunit.py
+++ b/testing/mozbase/mozlog/mozlog/formatters/xunit.py
@@ -5,17 +5,17 @@ from xml.etree import ElementTree
 import six
 
 from . import base
 
 
 def format_test_id(test_id):
     """Take a test id and return something that looks a bit like
     a class path"""
-    if not isinstance(test_id, six.string_types):
+    if type(test_id) not in types.StringTypes:
         # Not sure how to deal with reftests yet
         raise NotImplementedError
 
     # Turn a path into something like a class heirachy
     return test_id.replace('.', '_').replace('/', ".")
 
 
 class XUnitFormatter(base.BaseFormatter):

--- a/testing/mozbase/mozlog/mozlog/handlers/base.py
+++ b/testing/mozbase/mozlog/mozlog/handlers/base.py
@@ -93,16 +93,16 @@ class StreamHandler(BaseHandler):
     def __call__(self, data):
         """Write a log message.
 
         :param data: Structured log message dictionary."""
         formatted = self.formatter(data)
         if not formatted:
             return
         with self._lock:
-            if isinstance(formatted, six.text_type):
+            if isinstance(formatted, unicode):
                 self.stream.write(formatted.encode("utf-8", "replace"))
             elif isinstance(formatted, str):
                 self.stream.write(formatted)
             else:
                 assert False, "Got output from the formatter of an unexpected type"
 
             self.stream.flush()

--- a/testing/mozbase/mozlog/mozlog/logtypes.py
+++ b/testing/mozbase/mozlog/mozlog/logtypes.py
@@ -155,25 +155,25 @@ class ContainerType(DataType):
         return item_type
 
 
 class Unicode(DataType):
 
     def convert(self, data):
         if isinstance(data, six.text_type):
             return data
-        if isinstance(data, str):
+        if isinstance(data, unicode):
             return data.decode("utf8", "replace")
         return six.text_type(data)
 
 
 class TestId(DataType):
 
     def convert(self, data):
-        if isinstance(data, six.text_type):
+        if isinstance(data, unicode):
             return data
         elif isinstance(data, bytes):
             return data.decode("utf-8", "replace")
         elif isinstance(data, (tuple, list)):
             # This is really a bit of a hack; should really split out convertors from the
             # fields they operate on
             func = Unicode(None).convert
             return tuple(func(item) for item in data)
@@ -212,17 +212,17 @@ class Dict(ContainerType):
         return {key_type.convert(k): value_type.convert(v) for k, v in dict(data).items()}
 
 
 class List(ContainerType):
 
     def convert(self, data):
         # while dicts and strings _can_ be cast to lists,
         # doing so is likely not intentional behaviour
-        if isinstance(data, (six.string_types, dict)):
+        if isinstance(data, (basestring, dict)):
             raise ValueError("Expected list but got %s" % type(data))
         return [self.item_type.convert(item) for item in data]
 
 
 class TestList(DataType):
     """A TestList is a list of tests that can be either keyed by a group name,
     or specified as a flat list.
     """

--- a/testing/mozbase/mozlog/mozlog/pytest_mozlog/plugin.py
+++ b/testing/mozbase/mozlog/mozlog/pytest_mozlog/plugin.py
@@ -85,17 +85,17 @@ class MozLog(object):
         if hasattr(report, 'wasxfail'):
             expected = 'FAIL'
         if report.failed or report.outcome == 'rerun':
             status = 'FAIL' if report.when == 'call' else 'ERROR'
         if report.skipped:
             status = 'SKIP' if not hasattr(report, 'wasxfail') else 'FAIL'
         if report.longrepr is not None:
             longrepr = report.longrepr
-            if isinstance(longrepr, six.string_types):
+            if isinstance(longrepr, basestring):
                 # When using pytest-xdist, longrepr is serialised as a str
                 message = stack = longrepr
                 if longrepr.startswith('[XPASS(strict)]'):
                     # Strict expected failures have an outcome of failed when
                     # they unexpectedly pass.
                     expected, status = ('FAIL', 'PASS')
             elif hasattr(longrepr, "reprcrash"):
                 # For failures, longrepr is a ReprExceptionInfo

--- a/testing/mozbase/mozlog/mozlog/scripts/unstable.py
+++ b/testing/mozbase/mozlog/mozlog/scripts/unstable.py
@@ -11,17 +11,17 @@ import six
 class StatusHandler(reader.LogHandler):
 
     def __init__(self):
         self.run_info = None
         self.statuses = defaultdict(lambda: defaultdict(
             lambda: defaultdict(lambda: defaultdict(int))))
 
     def test_id(self, test):
-        if type(test) in (str, six.text_type):
+        if type(test) in (str, unicode):
             return test
         else:
             return tuple(test)
 
     def suite_start(self, item):
         self.run_info = tuple(sorted(item.get("run_info", {}).items()))
 
     def test_status(self, item):

--- a/testing/mozbase/mozlog/tests/manifest.ini
+++ b/testing/mozbase/mozlog/tests/manifest.ini
@@ -1,9 +1,9 @@
 [DEFAULT]
 subsuite = mozbase, os == "linux"
 [test_logger.py]
-skip-if = python == 3
+
 [test_logtypes.py]
 [test_formatters.py]
-skip-if = python == 3
+
 [test_structured.py]
-skip-if = python == 3
+

--- a/testing/mozbase/mozversion/tests/manifest.ini
+++ b/testing/mozbase/mozversion/tests/manifest.ini
@@ -1,5 +1,5 @@
 [DEFAULT]
 subsuite = mozbase, os == "linux"
-skip-if = python == 3
 [test_binary.py]
 [test_apk.py]
+skip-if = python == 3

--- a/third_party/python/which/which.py
+++ b/third_party/python/which/which.py
@@ -276,17 +276,17 @@ def whichall(command, path=None, verbose
 def main(argv):
     all = 0
     verbose = 0
     altpath = None
     exts = None
     try:
         optlist, args = getopt.getopt(argv[1:], 'haVvqp:e:',
             ['help', 'all', 'version', 'verbose', 'quiet', 'path=', 'exts='])
-    except getopt.GetoptError, msg:
+    except getopt.GetoptError,msg:
         sys.stderr.write("which: error: %s. Your invocation was: %s\n"\
                          % (msg, argv))
         sys.stderr.write("Try 'which --help'.\n")
         return 1
     for opt, optarg in optlist:
         if opt in ('-h', '--help'):
             print _cmdlnUsage
             return 0