SERVER-32295 Support Python 3

29 files changed, 353 insertions, 288 deletions

diff --git a/site_scons/libdeps.py b/site_scons/libdeps.py
index d2844a8d68b..e08104b0042 100644
--- a/site_scons/libdeps.py
+++ b/site_scons/libdeps.py
@@ -61,7 +61,7 @@ syslibdeps_env_var = 'SYSLIBDEPS'
 missing_syslibdep = 'MISSING_LIBDEP_'
 
 class dependency(object):
-    Public, Private, Interface = range(3)
+    Public, Private, Interface = list(range(3))
 
     def __init__(self, value, deptype):
         self.target_node = value
@@ -70,28 +70,31 @@ class dependency(object):
     def __str__(self):
         return str(self.target_node)
 
+
 dependency_visibility_ignored = {
-    dependency.Public : dependency.Public,
-    dependency.Private : dependency.Public,
-    dependency.Interface : dependency.Public,
+    dependency.Public: dependency.Public,
+    dependency.Private: dependency.Public,
+    dependency.Interface: dependency.Public,
 }
 
 dependency_visibility_honored = {
-    dependency.Public : dependency.Public,
-    dependency.Private : dependency.Private,
-    dependency.Interface : dependency.Interface,
+    dependency.Public: dependency.Public,
+    dependency.Private: dependency.Private,
+    dependency.Interface: dependency.Interface,
 }
 
+
 class DependencyCycleError(SCons.Errors.UserError):
     """Exception representing a cycle discovered in library dependencies."""
 
-    def __init__(self, first_node ):
+    def __init__(self, first_node):
         super(DependencyCycleError, self).__init__()
         self.cycle_nodes = [first_node]
 
     def __str__(self):
         return "Library dependency cycle detected: " + " => ".join(str(n) for n in self.cycle_nodes)
 
+
 def __get_sorted_direct_libdeps(node):
     direct_sorted = getattr(node.attributes, "libdeps_direct_sorted", False)
     if not direct_sorted:
@@ -100,8 +103,8 @@ def __get_sorted_direct_libdeps(node):
         setattr(node.attributes, "libdeps_direct_sorted", direct_sorted)
     return direct_sorted
 
-def __get_libdeps(node):
 
+def __get_libdeps(node):
     """Given a SCons Node, return its library dependencies, topologically sorted.
 
     Computes the dependencies if they're not already cached.
@@ -133,7 +136,7 @@ def __get_libdeps(node):
                 marked.add(n.target_node)
                 tsorted.append(n.target_node)
 
-            except DependencyCycleError, e:
+            except DependencyCycleError as e:
                 if len(e.cycle_nodes) == 1 or e.cycle_nodes[0] != e.cycle_nodes[-1]:
                     e.cycle_nodes.insert(0, n.target_node)
                 raise
@@ -150,6 +153,7 @@ def __get_libdeps(node):
 
     return tsorted
 
+
 def __get_syslibdeps(node):
     """ Given a SCons Node, return its system library dependencies.
 
@@ -161,11 +165,11 @@ def __get_syslibdeps(node):
         for lib in __get_libdeps(node):
             for syslib in node.get_env().Flatten(lib.get_env().get(syslibdeps_env_var, [])):
                 if syslib:
-                    if type(syslib) in (str, unicode) and syslib.startswith(missing_syslibdep):
-                        print("Target '%s' depends on the availability of a "
+                    if type(syslib) is str and syslib.startswith(missing_syslibdep):
+                        print(("Target '%s' depends on the availability of a "
                               "system provided library for '%s', "
                               "but no suitable library was found during configuration." %
-                              (str(node), syslib[len(missing_syslibdep):]))
+                              (str(node), syslib[len(missing_syslibdep):])))
                         node.get_env().Exit(1)
                     syslibdeps.append(syslib)
         setattr(node.attributes, cached_var_name, syslibdeps)
@@ -181,17 +185,20 @@ def update_scanner(builder):
 
     if old_scanner:
         path_function = old_scanner.path_function
+
         def new_scanner(node, env, path=()):
             result = old_scanner.function(node, env, path)
             result.extend(__get_libdeps(node))
             return result
     else:
         path_function = None
+
         def new_scanner(node, env, path=()):
             return __get_libdeps(node)
 
     builder.target_scanner = SCons.Scanner.Scanner(function=new_scanner,
-                                                    path_function=path_function)
+                                                   path_function=path_function)
+
 
 def get_libdeps(source, target, env, for_signature):
     """Implementation of the special _LIBDEPS environment variable.
@@ -202,6 +209,7 @@ def get_libdeps(source, target, env, for_signature):
     target = env.Flatten([target])
     return __get_libdeps(target[0])
 
+
 def get_libdeps_objs(source, target, env, for_signature):
     objs = []
     for lib in get_libdeps(source, target, env, for_signature):
@@ -209,6 +217,7 @@ def get_libdeps_objs(source, target, env, for_signature):
         objs.extend(lib.sources)
     return objs
 
+
 def get_syslibdeps(source, target, env, for_signature):
     deps = __get_syslibdeps(target[0])
     lib_link_prefix = env.subst('$LIBLINKPREFIX')
@@ -220,7 +229,7 @@ def get_syslibdeps(source, target, env, for_signature):
         # they're believed to represent library short names, that should be prefixed with -l
         # or the compiler-specific equivalent.  I.e., 'm' becomes '-lm', but 'File("m.a") is passed
         # through whole cloth.
-        if type(d) in (str, unicode):
+        if type(d) is str:
             result.append('%s%s%s' % (lib_link_prefix, d, lib_link_suffix))
         else:
             result.append(d)
@@ -234,8 +243,9 @@ def __append_direct_libdeps(node, prereq_nodes):
         node.attributes.libdeps_direct = []
     node.attributes.libdeps_direct.extend(prereq_nodes)
 
-def make_libdeps_emitter(dependency_builder, dependency_map=dependency_visibility_ignored, ignore_progdeps=False):
 
+def make_libdeps_emitter(dependency_builder, dependency_map=dependency_visibility_ignored,
+                         ignore_progdeps=False):
     def libdeps_emitter(target, source, env):
         """SCons emitter that takes values from the LIBDEPS environment variable and
         converts them to File node objects, binding correct path information into
@@ -260,13 +270,20 @@ def make_libdeps_emitter(dependency_builder, dependency_map=dependency_visibilit
         prog_builder = env['BUILDERS']['Program']
         prog_node_factory = prog_builder.target_factory or env.File
 
-        prereqs = [dependency(l, dependency_map[dependency.Public]) for l in env.get(libdeps_env_var, []) if l]
-        prereqs.extend(dependency(l, dependency_map[dependency.Interface]) for l in env.get(libdeps_env_var + '_INTERFACE', []) if l)
-        prereqs.extend(dependency(l, dependency_map[dependency.Private]) for l in env.get(libdeps_env_var + '_PRIVATE', []) if l)
+        prereqs = [
+            dependency(l, dependency_map[dependency.Public]) for l in env.get(libdeps_env_var, [])
+            if l
+        ]
+        prereqs.extend(
+            dependency(l, dependency_map[dependency.Interface])
+            for l in env.get(libdeps_env_var + '_INTERFACE', []) if l)
+        prereqs.extend(
+            dependency(l, dependency_map[dependency.Private])
+            for l in env.get(libdeps_env_var + '_PRIVATE', []) if l)
 
         for prereq in prereqs:
-            prereqWithIxes = SCons.Util.adjustixes(
-                prereq.target_node, lib_builder.get_prefix(env), lib_builder.get_suffix(env))
+            prereqWithIxes = SCons.Util.adjustixes(prereq.target_node, lib_builder.get_prefix(env),
+                                                   lib_builder.get_suffix(env))
             prereq.target_node = lib_node_factory(prereqWithIxes)
 
         for t in target:
@@ -283,10 +300,11 @@ def make_libdeps_emitter(dependency_builder, dependency_map=dependency_visibilit
                 visibility = dependent[1]
                 dependent = dependent[0]
 
-            dependentWithIxes = SCons.Util.adjustixes(
-                dependent, lib_builder.get_prefix(env), lib_builder.get_suffix(env))
+            dependentWithIxes = SCons.Util.adjustixes(dependent, lib_builder.get_prefix(env),
+                                                      lib_builder.get_suffix(env))
             dependentNode = lib_node_factory(dependentWithIxes)
-            __append_direct_libdeps(dependentNode, [dependency(target[0], dependency_map[visibility])])
+            __append_direct_libdeps(dependentNode,
+                                    [dependency(target[0], dependency_map[visibility])])
 
         if not ignore_progdeps:
             for dependent in env.get('PROGDEPS_DEPENDENTS', []):
@@ -299,21 +317,24 @@ def make_libdeps_emitter(dependency_builder, dependency_map=dependency_visibilit
                     visibility = dependent[1]
                     dependent = dependent[0]
 
-                dependentWithIxes = SCons.Util.adjustixes(
-                    dependent, prog_builder.get_prefix(env), prog_builder.get_suffix(env))
+                dependentWithIxes = SCons.Util.adjustixes(dependent, prog_builder.get_prefix(env),
+                                                          prog_builder.get_suffix(env))
                 dependentNode = prog_node_factory(dependentWithIxes)
-                __append_direct_libdeps(dependentNode, [dependency(target[0], dependency_map[visibility])])
+                __append_direct_libdeps(dependentNode,
+                                        [dependency(target[0], dependency_map[visibility])])
 
         return target, source
 
     return libdeps_emitter
 
+
 def expand_libdeps_tags(source, target, env, for_signature):
     results = []
     for expansion in env.get('LIBDEPS_TAG_EXPANSIONS', []):
         results.append(expansion(source, target, env, for_signature))
     return results
 
+
 def setup_environment(env, emitting_shared=False):
     """Set up the given build environment to do LIBDEPS tracking."""
 
@@ -339,19 +360,18 @@ def setup_environment(env, emitting_shared=False):
     def make_indirect_emitter(variable):
         def indirect_emitter(target, source, env):
             return env[variable](target, source, env)
+
         return indirect_emitter
 
     env.Append(
         LIBDEPS_LIBEMITTER=make_libdeps_emitter('StaticLibrary'),
         LIBEMITTER=make_indirect_emitter('LIBDEPS_LIBEMITTER'),
-
         LIBDEPS_SHAREMITTER=make_libdeps_emitter('SharedArchive', ignore_progdeps=True),
         SHAREMITTER=make_indirect_emitter('LIBDEPS_SHAREMITTER'),
-
         LIBDEPS_SHLIBEMITTER=make_libdeps_emitter('SharedLibrary', dependency_visibility_honored),
         SHLIBEMITTER=make_indirect_emitter('LIBDEPS_SHLIBEMITTER'),
-
-        LIBDEPS_PROGEMITTER=make_libdeps_emitter('SharedLibrary' if emitting_shared else 'StaticLibrary'),
+        LIBDEPS_PROGEMITTER=make_libdeps_emitter(
+            'SharedLibrary' if emitting_shared else 'StaticLibrary'),
         PROGEMITTER=make_indirect_emitter('LIBDEPS_PROGEMITTER'),
     )
 
@@ -362,9 +382,11 @@ def setup_environment(env, emitting_shared=False):
             if 'init-no-global-side-effects' in env.Entry(lib).get_env().get('LIBDEPS_TAGS', []):
                 result.append(str(lib))
             else:
-                result.extend(env.subst('$LINK_WHOLE_ARCHIVE_LIB_START'
-                                        '$TARGET'
-                                        '$LINK_WHOLE_ARCHIVE_LIB_END', target=lib).split())
+                result.extend(
+                    env.subst(
+                        '$LINK_WHOLE_ARCHIVE_LIB_START'
+                        '$TARGET'
+                        '$LINK_WHOLE_ARCHIVE_LIB_END', target=lib).split())
         return result
 
     env['_LIBDEPS_LIBS_WITH_TAGS'] = expand_libdeps_with_extraction_flags
@@ -382,6 +404,7 @@ def setup_environment(env, emitting_shared=False):
         except KeyError:
             pass
 
+
 def setup_conftests(conf):
     def FindSysLibDep(context, name, libs, **kwargs):
         var = "LIBDEPS_" + name.upper() + "_SYSLIBDEP"
@@ -394,4 +417,5 @@ def setup_conftests(conf):
                 return context.Result(result)
         context.env[var] = __missing_syslib(name)
         return context.Result(result)
+
     conf.AddTest('FindSysLibDep', FindSysLibDep)
diff --git a/site_scons/mongo/__init__.py b/site_scons/mongo/__init__.py
index 510bd7bcc2f..f77478092b9 100644
--- a/site_scons/mongo/__init__.py
+++ b/site_scons/mongo/__init__.py
@@ -5,4 +5,4 @@
 def print_build_failures():
     from SCons.Script import GetBuildFailures
     for bf in GetBuildFailures():
-        print "%s failed: %s" % (bf.node, bf.errstr)
+        print("%s failed: %s" % (bf.node, bf.errstr))
diff --git a/site_scons/mongo/generators.py b/site_scons/mongo/generators.py
index c07e86a4d14..052f18d3a0a 100644
--- a/site_scons/mongo/generators.py
+++ b/site_scons/mongo/generators.py
@@ -1,6 +1,6 @@
 # -*- mode: python; -*-
 
-import md5
+import hashlib
 
 # Default and alternative generator definitions go here.
 
@@ -15,22 +15,69 @@ import md5
 # want to define them.
 def default_buildinfo_environment_data():
     return (
-        ('distmod', '$MONGO_DISTMOD', True, True,),
-        ('distarch', '$MONGO_DISTARCH', True, True,),
-        ('cc', '$CC_VERSION', True, False,),
-        ('ccflags', '$CCFLAGS', True, False,),
-        ('cxx', '$CXX_VERSION', True, False,),
-        ('cxxflags', '$CXXFLAGS', True, False,),
-        ('linkflags', '$LINKFLAGS', True, False,),
-        ('target_arch', '$TARGET_ARCH', True, True,),
-        ('target_os', '$TARGET_OS', True, False,),
+        (
+            'distmod',
+            '$MONGO_DISTMOD',
+            True,
+            True,
+        ),
+        (
+            'distarch',
+            '$MONGO_DISTARCH',
+            True,
+            True,
+        ),
+        (
+            'cc',
+            '$CC_VERSION',
+            True,
+            False,
+        ),
+        (
+            'ccflags',
+            '$CCFLAGS',
+            True,
+            False,
+        ),
+        (
+            'cxx',
+            '$CXX_VERSION',
+            True,
+            False,
+        ),
+        (
+            'cxxflags',
+            '$CXXFLAGS',
+            True,
+            False,
+        ),
+        (
+            'linkflags',
+            '$LINKFLAGS',
+            True,
+            False,
+        ),
+        (
+            'target_arch',
+            '$TARGET_ARCH',
+            True,
+            True,
+        ),
+        (
+            'target_os',
+            '$TARGET_OS',
+            True,
+            False,
+        ),
     )
 
+
 # If you want buildInfo and --version to be relatively empty, set
 # MONGO_BUILDINFO_ENVIRONMENT_DATA = empty_buildinfo_environment_data()
 def empty_buildinfo_environment_data():
     return ()
 
+
 def default_variant_dir_generator(target, source, env, for_signature):
 
     if env.GetOption('cache') != None:
@@ -44,11 +91,11 @@ def default_variant_dir_generator(target, source, env, for_signature):
 
     # Hash the named options and their values, and take the first 8 characters of the hash as
     # the variant name
-    hasher = md5.md5()
+    hasher = hashlib.md5()
     for option in variant_options:
-        hasher.update(option)
-        hasher.update(str(env.GetOption(option)))
-    variant_dir = hasher.hexdigest()[0:8]
+        hasher.update(option.encode('utf-8'))
+        hasher.update(str(env.GetOption(option)).encode('utf-8'))
+    variant_dir = str(hasher.hexdigest()[0:8])
 
     # If our option hash yields a well known hash, replace it with its name.
     known_variant_hashes = {
diff --git a/site_scons/mongo/platform.py b/site_scons/mongo/platform.py
index 05df9017ac4..f5d15b4924c 100644
--- a/site_scons/mongo/platform.py
+++ b/site_scons/mongo/platform.py
@@ -1,5 +1,4 @@
 # -*- mode: python; -*-
-
 """
 Support code related to OS detection in general. System specific facilities or customization
 hooks live in mongo_platform_<PLATFORM>.py files.
@@ -12,6 +11,7 @@ import os
 # This needs to precede the options section so that we can only offer some options on certain
 # operating systems.
 
+
 # This function gets the running OS as identified by Python
 # It should only be used to set up defaults for options/variables, because
 # its value could potentially be overridden by setting TARGET_OS on the
@@ -34,25 +34,28 @@ def get_running_os_name():
         running_os = 'unknown'
     return running_os
 
+
 def env_get_os_name_wrapper(self):
     return self['TARGET_OS']
 
+
 def is_os_raw(target_os, os_list_to_check):
-    darwin_os_list = [ 'macOS', 'tvOS', 'tvOS-sim', 'iOS', 'iOS-sim', 'watchOS', 'watchOS-sim' ]
-    linux_os_list = [ 'android', 'linux' ]
-    posix_os_list = [ 'openbsd', 'freebsd', 'solaris', 'emscripten' ] + darwin_os_list + linux_os_list
+    darwin_os_list = ['macOS', 'tvOS', 'tvOS-sim', 'iOS', 'iOS-sim', 'watchOS', 'watchOS-sim']
+    linux_os_list = ['android', 'linux']
+    posix_os_list = ['openbsd', 'freebsd', 'solaris', 'emscripten'] + darwin_os_list + linux_os_list
 
     os_families = {
-            "darwin": darwin_os_list,
-            "posix": posix_os_list,
-            "linux": linux_os_list,
+        "darwin": darwin_os_list,
+        "posix": posix_os_list,
+        "linux": linux_os_list,
     }
 
     for os in os_list_to_check:
-        if os == target_os or ( os in os_families and target_os in os_families[os] ):
+        if os == target_os or (os in os_families and target_os in os_families[os]):
             return True
     return False
 
+
 # This function tests the running OS as identified by Python
 # It should only be used to set up defaults for options/variables, because
 # its value could potentially be overridden by setting TARGET_OS on the
@@ -60,5 +63,6 @@ def is_os_raw(target_os, os_list_to_check):
 def is_running_os(*os_list):
     return is_os_raw(get_running_os_name(), os_list)
 
+
 def env_os_is_wrapper(self, *os_list):
     return is_os_raw(self['TARGET_OS'], os_list)
diff --git a/site_scons/mongo/toolchain.py b/site_scons/mongo/toolchain.py
index ffa74f56f6f..9bab92a68b7 100644
--- a/site_scons/mongo/toolchain.py
+++ b/site_scons/mongo/toolchain.py
@@ -6,31 +6,22 @@ import SCons
 
 # Helper functions for generic toolchain things go here
 
+
 def get_toolchain_ver(env, tool):
     # By default we don't know the version of each tool, and only report what
     # command gets executed (gcc vs /opt/mongodbtoolchain/bin/gcc).
     verstr = "version unknown"
     proc = None
     if env.ToolchainIs('clang', 'gcc'):
-        proc = SCons.Action._subproc(env,
-            env.subst("${%s} --version" % tool),
-            stdout=subprocess.PIPE,
-            stderr='devnull',
-            stdin='devnull',
-            universal_newlines=True,
-            error='raise',
-            shell=True)
+        proc = SCons.Action._subproc(env, env.subst("${%s} --version" % tool),
+                                     stdout=subprocess.PIPE, stderr='devnull', stdin='devnull',
+                                     universal_newlines=True, error='raise', shell=True)
         verstr = proc.stdout.readline()
 
     elif env.ToolchainIs('msvc') and env.TargetOSIs('windows'):
-        proc = SCons.Action._subproc(env,
-            env.subst("${%s}" % tool),
-            stdout='devnull',
-            stderr=subprocess.PIPE,
-            stdin='devnull',
-            universal_newlines=True,
-            error='raise',
-            shell=True)
+        proc = SCons.Action._subproc(env, env.subst("${%s}" % tool), stdout='devnull',
+                                     stderr=subprocess.PIPE, stdin='devnull',
+                                     universal_newlines=True, error='raise', shell=True)
         verstr = proc.stderr.readline()
 
     # If we started a process, we should drain its stdout/stderr and wait for
diff --git a/site_scons/site_tools/abilink.py b/site_scons/site_tools/abilink.py
index 65f2a995719..00f5e71a0a3 100644
--- a/site_scons/site_tools/abilink.py
+++ b/site_scons/site_tools/abilink.py
@@ -20,6 +20,7 @@ import subprocess
 # TODO: Make a variable for the md5sum utility (allow any hasher)
 # TODO: Add an ABILINKCOM variable to the Action, so it can be silenced.
 
+
 def _detect(env):
     try:
         abidw = env['ABIDW']
@@ -31,6 +32,7 @@ def _detect(env):
 
     return env.WhereIs('abidw')
 
+
 def _add_emitter(builder):
     base_emitter = builder.emitter
 
@@ -47,6 +49,7 @@ def _add_emitter(builder):
     new_emitter = SCons.Builder.ListEmitter([base_emitter, new_emitter])
     builder.emitter = new_emitter
 
+
 def _add_scanner(builder):
     old_scanner = builder.target_scanner
     path_function = old_scanner.path_function
@@ -59,16 +62,21 @@ def _add_scanner(builder):
             new_results.append(abidw if abidw else base)
         return new_results
 
-    builder.target_scanner = SCons.Scanner.Scanner(function=new_scanner, path_function=path_function)
+    builder.target_scanner = SCons.Scanner.Scanner(function=new_scanner,
+                                                   path_function=path_function)
+
 
 def _add_action(builder):
     actions = builder.action
-    builder.action = actions + SCons.Action.Action("$ABIDW --no-show-locs $TARGET | md5sum > ${TARGET}.abidw")
+    builder.action = actions + SCons.Action.Action(
+        "$ABIDW --no-show-locs $TARGET | md5sum > ${TARGET}.abidw")
+
 
 def exists(env):
     result = _detect(env) != None
     return result
 
+
 def generate(env):
 
     if not exists(env):
diff --git a/site_scons/site_tools/auto_install_binaries.py b/site_scons/site_tools/auto_install_binaries.py
index 9a71b4919b7..6261058c268 100644
--- a/site_scons/site_tools/auto_install_binaries.py
+++ b/site_scons/site_tools/auto_install_binaries.py
@@ -1,24 +1,26 @@
 import SCons
 
+
 def exists(env):
     return True
 
+
 def generate(env):
 
     env.Tool('install')
 
     suffix_map = {
-        env.subst('$PROGSUFFIX') : 'bin',
-        '.dylib' : 'lib',
+        env.subst('$PROGSUFFIX'): 'bin',
+        '.dylib': 'lib',
         # TODO: These 'lib' answers are incorrect. The location for the debug info
         # should be the same as the target itself, which might be bin or lib. We need
         # a solution for that. When that is fixed, add 'Program' back into the list
         # of separate debug targets in the separate_debug.py tool.
-        '.dSYM' : 'lib',
-        '.debug' : 'lib',
-        '.so' : 'lib',
-        '.dll' : 'bin',
-        '.lib' : 'lib',
+        '.dSYM': 'lib',
+        '.debug': 'lib',
+        '.so': 'lib',
+        '.dll': 'bin',
+        '.lib': 'lib',
     }
 
     def auto_install(env, target, source, **kwargs):
@@ -67,7 +69,8 @@ def generate(env):
             if auto_install_location:
                 tentry_install_tags = env.get('INSTALL_ALIAS', [])
                 setattr(tentry.attributes, 'INSTALL_ALIAS', tentry_install_tags)
-                install = env.AutoInstall(auto_install_location, tentry, INSTALL_ALIAS=tentry_install_tags)
+                install = env.AutoInstall(auto_install_location, tentry,
+                                          INSTALL_ALIAS=tentry_install_tags)
         return (target, source)
 
     def add_emitter(builder):
@@ -99,7 +102,7 @@ def generate(env):
 
     from SCons.Tool import install
     base_install_builder = install.BaseInstallBuilder
-    assert(base_install_builder.target_scanner == None)
+    assert (base_install_builder.target_scanner == None)
 
     base_install_builder.target_scanner = SCons.Scanner.Scanner(
         function=scan_for_transitive_install,
diff --git a/site_scons/site_tools/compilation_db.py b/site_scons/site_tools/compilation_db.py
index 161ac6061ea..07aa2d96e58 100644
--- a/site_scons/site_tools/compilation_db.py
+++ b/site_scons/site_tools/compilation_db.py
@@ -28,7 +28,7 @@ import itertools
 # compilation database can access the complete list, and also so that the writer has easy
 # access to write all of the files. But it seems clunky. How can the emitter and the scanner
 # communicate more gracefully?
-__COMPILATION_DB_ENTRIES=[]
+__COMPILATION_DB_ENTRIES = []
 
 # Cribbed from Tool/cc.py and Tool/c++.py. It would be better if
 # we could obtain this from SCons.
@@ -40,6 +40,7 @@ _CXXSuffixes = ['.cpp', '.cc', '.cxx', '.c++', '.C++']
 if SCons.Util.case_sensitive_suffixes('.c', '.C'):
     _CXXSuffixes.append('.C')
 
+
 # We make no effort to avoid rebuilding the entries. Someday, perhaps we could and even
 # integrate with the cache, but there doesn't seem to be much call for it.
 class __CompilationDbNode(SCons.Node.Python.Value):
@@ -77,11 +78,8 @@ def makeEmitCompilationDbEntry(comstr):
         dbtarget = __CompilationDbNode(source)
 
         entry = env.__COMPILATIONDB_Entry(
-            target=dbtarget,
-            source=[],
-            __COMPILATIONDB_UTARGET=target,
-            __COMPILATIONDB_USOURCE=source,
-            __COMPILATIONDB_UACTION=user_action,
+            target=dbtarget, source=[], __COMPILATIONDB_UTARGET=target,
+            __COMPILATIONDB_USOURCE=source, __COMPILATIONDB_UACTION=user_action,
             __COMPILATIONDB_ENV=env)
 
         # TODO: Technically, these next two lines should not be required: it should be fine to
@@ -112,11 +110,11 @@ def CompilationDbEntryAction(target, source, env, **kw):
     command = env['__COMPILATIONDB_UACTION'].strfunction(
         target=env['__COMPILATIONDB_UTARGET'],
         source=env['__COMPILATIONDB_USOURCE'],
-        env=env['__COMPILATIONDB_ENV'],)
+        env=env['__COMPILATIONDB_ENV'],
+    )
 
     entry = {
-        "directory": env.Dir('#').abspath,
-        "command": command,
+        "directory": env.Dir('#').abspath, "command": command,
         "file": str(env['__COMPILATIONDB_USOURCE'][0])
     }
 
@@ -130,21 +128,19 @@ def WriteCompilationDb(target, source, env):
         entries.append(s.read())
 
     with open(str(target[0]), 'w') as target_file:
-        json.dump(entries, target_file,
-                  sort_keys=True,
-                  indent=4,
-                  separators=(',', ': '))
+        json.dump(entries, target_file, sort_keys=True, indent=4, separators=(',', ': '))
 
 
 def ScanCompilationDb(node, env, path):
     return __COMPILATION_DB_ENTRIES
 
+
 def generate(env, **kwargs):
 
     static_obj, shared_obj = SCons.Tool.createObjBuilders(env)
 
-    env['COMPILATIONDB_COMSTR'] = kwargs.get(
-        'COMPILATIONDB_COMSTR', 'Building compilation database $TARGET')
+    env['COMPILATIONDB_COMSTR'] = kwargs.get('COMPILATIONDB_COMSTR',
+                                             'Building compilation database $TARGET')
 
     components_by_suffix = itertools.chain(
         itertools.product(_CSuffixes, [
@@ -163,28 +159,20 @@ def generate(env, **kwargs):
 
         # Assumes a dictionary emitter
         emitter = builder.emitter[suffix]
-        builder.emitter[suffix] = SCons.Builder.ListEmitter(
-            [
-                emitter,
-                makeEmitCompilationDbEntry(command),
-            ]
-        )
+        builder.emitter[suffix] = SCons.Builder.ListEmitter([
+            emitter,
+            makeEmitCompilationDbEntry(command),
+        ])
 
     env['BUILDERS']['__COMPILATIONDB_Entry'] = SCons.Builder.Builder(
-        action=SCons.Action.Action(CompilationDbEntryAction, None),
-    )
+        action=SCons.Action.Action(CompilationDbEntryAction, None), )
 
     env['BUILDERS']['__COMPILATIONDB_Database'] = SCons.Builder.Builder(
         action=SCons.Action.Action(WriteCompilationDb, "$COMPILATIONDB_COMSTR"),
-        target_scanner=SCons.Scanner.Scanner(
-            function=ScanCompilationDb,
-            node_class=None)
-    )
+        target_scanner=SCons.Scanner.Scanner(function=ScanCompilationDb, node_class=None))
 
     def CompilationDatabase(env, target):
-        result = env.__COMPILATIONDB_Database(
-            target=target,
-            source=[])
+        result = env.__COMPILATIONDB_Database(target=target, source=[])
 
         env.AlwaysBuild(result)
         env.NoCache(result)
@@ -193,5 +181,6 @@ def generate(env, **kwargs):
 
     env.AddMethod(CompilationDatabase, 'CompilationDatabase')
 
+
 def exists(env):
     return True
diff --git a/site_scons/site_tools/dagger/__init__.py b/site_scons/site_tools/dagger/__init__.py
index f05228cfe45..c63bfc6967e 100644
--- a/site_scons/site_tools/dagger/__init__.py
+++ b/site_scons/site_tools/dagger/__init__.py
@@ -5,7 +5,7 @@ import logging
 
 import SCons
 
-import dagger
+from . import dagger
 
 def generate(env, **kwargs):
     """The entry point for our tool. However, the builder for
@@ -14,25 +14,22 @@ def generate(env, **kwargs):
     to the native builders for object/libraries.
     """
 
-    env.Replace(LIBEMITTER=SCons.Builder.ListEmitter([env['LIBEMITTER'],
-                                                      dagger.emit_lib_db_entry]))
+    env.Replace(LIBEMITTER=SCons.Builder.ListEmitter([env['LIBEMITTER'], dagger.emit_lib_db_entry]))
     running_os = os.sys.platform
 
     if not (running_os.startswith('win') or running_os.startswith('sun')):
-        env.Replace(PROGEMITTER=SCons.Builder.ListEmitter([env['PROGEMITTER'],
-        dagger.emit_prog_db_entry]))
+        env.Replace(
+            PROGEMITTER=SCons.Builder.ListEmitter([env['PROGEMITTER'], dagger.emit_prog_db_entry]))
 
     static_obj, shared_obj = SCons.Tool.createObjBuilders(env)
     suffixes = ['.c', '.cc', '.cxx', '.cpp']
     obj_builders = [static_obj, shared_obj]
-    default_emitters = [SCons.Defaults.StaticObjectEmitter,
-                        SCons.Defaults.SharedObjectEmitter]
+    default_emitters = [SCons.Defaults.StaticObjectEmitter, SCons.Defaults.SharedObjectEmitter]
 
     for suffix in suffixes:
         for i in range(len(obj_builders)):
-            obj_builders[i].add_emitter(suffix, SCons.Builder.ListEmitter([
-                dagger.emit_obj_db_entry, default_emitters[i]
-            ]))
+            obj_builders[i].add_emitter(
+                suffix, SCons.Builder.ListEmitter([dagger.emit_obj_db_entry, default_emitters[i]]))
 
     env['BUILDERS']['__OBJ_DATABASE'] = SCons.Builder.Builder(
         action=SCons.Action.Action(dagger.write_obj_db, None))
diff --git a/site_scons/site_tools/dagger/dagger.py b/site_scons/site_tools/dagger/dagger.py
index bace834783b..cc208dd23c2 100644
--- a/site_scons/site_tools/dagger/dagger.py
+++ b/site_scons/site_tools/dagger/dagger.py
@@ -40,8 +40,8 @@ import sys
 
 import SCons
 
-import graph
-import graph_consts
+from . import graph
+from . import graph_consts
 
 
 LIB_DB = [] # Stores every SCons library nodes
@@ -92,11 +92,9 @@ def get_symbol_worker(object_file, task):
     uses = p.communicate()[0].decode()
 
     if platform == 'linux':
-        return list_process([use[19:] for use in uses.split('\n')
-                             if use != ''])
+        return list_process([use[19:] for use in uses.split('\n') if use != ''])
     elif platform == 'darwin':
-        return list_process([use.strip() for use in uses.split('\n')
-                             if use != ''])
+        return list_process([use.strip() for use in uses.split('\n') if use != ''])
 
 
 def emit_obj_db_entry(target, source, env):
@@ -109,6 +107,7 @@ def emit_obj_db_entry(target, source, env):
         OBJ_DB.append(t)
     return target, source
 
+
 def emit_prog_db_entry(target, source, env):
     for t in target:
         if str(t) is None:
@@ -117,6 +116,7 @@ def emit_prog_db_entry(target, source, env):
 
     return target, source
 
+
 def emit_lib_db_entry(target, source, env):
     """Emitter for libraries. We add each library
     into our global variable"""
@@ -210,6 +210,7 @@ def __generate_file_rels(obj, g):
         for obj in objs:
             g.add_edge(graph_consts.FIL_FIL, file_node.id, obj)
 
+
 def __generate_exe_rels(exe, g):
     """Generates all executable to library relationships, and populates the
     contained files field in each NodeExe object"""
@@ -223,6 +224,7 @@ def __generate_exe_rels(exe, g):
 
     exe_node.contained_files = set(EXE_DB[exe])
 
+
 def write_obj_db(target, source, env):
     """The bulk of the tool. This method takes all the objects and libraries
     which we have stored in the global LIB_DB and OBJ_DB variables and
@@ -240,7 +242,7 @@ def write_obj_db(target, source, env):
     for obj in OBJ_DB:
         __generate_file_rels(obj, g)
 
-    for exe in EXE_DB.keys():
+    for exe in list(EXE_DB.keys()):
         __generate_exe_rels(exe, g)
 
     # target is given as a list of target SCons nodes - this builder is only responsible for
diff --git a/site_scons/site_tools/dagger/graph.py b/site_scons/site_tools/dagger/graph.py
index 5ebe6f45061..40c7fd9b2d9 100644
--- a/site_scons/site_tools/dagger/graph.py
+++ b/site_scons/site_tools/dagger/graph.py
@@ -4,10 +4,7 @@ import abc
 import json
 import copy
 
-import graph_consts
-
-if sys.version_info >= (3, 0):
-    basestring = str
+from . import graph_consts
 
 class Graph(object):
     """Graph class for storing the build dependency graph. The graph stores the
@@ -20,7 +17,7 @@ class Graph(object):
         """
         A graph can be initialized with a .json file, graph object, or with no args
         """
-        if isinstance(input, basestring):
+        if isinstance(input, str):
             if input.endswith('.json'):
                 with open(input, 'r') as f:
                     data = json.load(f, encoding="ascii")
@@ -72,7 +69,7 @@ class Graph(object):
 
     @nodes.setter
     def nodes(self, value):
-        if isinstance(value,dict):
+        if isinstance(value, dict):
             self._nodes = value
         else:
             raise TypeError("Nodes must be a dict")
@@ -141,7 +138,7 @@ class Graph(object):
             node_dict["id"] = id
             node_dict["node"] = {}
 
-            for property, value in vars(node).iteritems():
+            for property, value in vars(node).items():
                 if isinstance(value, set):
                     node_dict["node"][property] = list(value)
                 else:
@@ -151,7 +148,7 @@ class Graph(object):
 
         for edge_type in graph_consts.RELATIONSHIP_TYPES:
             edges_dict = self._edges[edge_type]
-            for node in edges_dict.keys():
+            for node in list(edges_dict.keys()):
                 to_nodes = list(self._edges[edge_type][node])
                 to_nodes_dicts = [{"index": node_index[to_node], "id": to_node}
                                   for to_node in to_nodes]
@@ -166,14 +163,13 @@ class Graph(object):
 
     def __str__(self):
         return ("<Number of Nodes : {0}, Number of Edges : {1}, "
-                "Hash: {2}>").format(len(self._nodes.keys()),
-                sum(len(x) for x in self._edges.values()), hash(self))
+                "Hash: {2}>").format(len(list(self._nodes.keys())),
+                sum(len(x) for x in list(self._edges.values())), hash(self))
 
 
-class NodeInterface(object):
+class NodeInterface(object, metaclass=abc.ABCMeta):
     """Abstract base class for all Node Objects - All nodes must have an id and name
     """
-    __metaclass__ = abc.ABCMeta
 
     @abc.abstractproperty
     def id(self):
@@ -190,7 +186,7 @@ class NodeLib(NodeInterface):
     def __init__(self, id, name, input=None):
         if isinstance(input, dict):
             should_fail = False
-            for k, v in input.iteritems():
+            for k, v in input.items():
                 try:
                     if isinstance(v, list):
                         setattr(self, k, set(v))
@@ -287,10 +283,10 @@ class NodeLib(NodeInterface):
 
     def __eq__(self, other):
         if isinstance(other, NodeLib):
-            return (self._id == other._id and self._defined_symbols == other._defined_symbols and
-                    self._defined_files == other._defined_files and
-                    self._dependent_libs == other._dependent_libs and
-                    self._dependent_files == other._dependent_files)
+            return (self._id == other._id and self._defined_symbols == other._defined_symbols
+                    and self._defined_files == other._defined_files
+                    and self._dependent_libs == other._dependent_libs
+                    and self._dependent_files == other._dependent_files)
 
         else:
             return False
@@ -310,7 +306,7 @@ class NodeSymbol(NodeInterface):
         if isinstance(input, dict):
             should_fail = False
 
-            for k, v in input.iteritems():
+            for k, v in input.items():
                 try:
                     if isinstance(v, list):
                         setattr(self, k, set(v))
@@ -413,11 +409,10 @@ class NodeSymbol(NodeInterface):
 
     def __eq__(self, other):
         if isinstance(other, NodeSymbol):
-            return (self.id == other.id and self._libs == other._libs and
-                    self._files == other._files and
-                    self._dependent_libs == other._dependent_libs and
-                    self._dependent_files == other._dependent_files
-                    )
+            return (self.id == other.id and self._libs == other._libs
+                    and self._files == other._files
+                    and self._dependent_libs == other._dependent_libs
+                    and self._dependent_files == other._dependent_files)
         else:
             return False
 
@@ -435,7 +430,7 @@ class NodeFile(NodeInterface):
     def __init__(self, id, name, input=None):
         if isinstance(input, dict):
             should_fail = False
-            for k, v in input.iteritems():
+            for k, v in input.items():
                 try:
                     if isinstance(v, list):
                         setattr(self, k, set(v))
@@ -526,16 +521,16 @@ class NodeFile(NodeInterface):
                 self.add_dependent_lib(from_node.library)
                 g.add_edge(graph_consts.LIB_FIL, from_node.library, self.id)
                 if lib_node is not None:
-                        lib_node.add_dependent_file(from_node.id)
-                        lib_node.add_dependent_lib(from_node.library)
-                        g.add_edge(graph_consts.FIL_LIB, from_node.id, lib_node.id)
+                    lib_node.add_dependent_file(from_node.id)
+                    lib_node.add_dependent_lib(from_node.library)
+                    g.add_edge(graph_consts.FIL_LIB, from_node.id, lib_node.id)
 
     def __eq__(self, other):
         if isinstance(other, NodeSymbol):
-            return (self.id == other.id and self._lib == other._lib and
-                    self._dependent_libs == other._dependent_libs and
-                    self._dependent_files == other._dependent_files and
-                    self._defined_symbols == other._defined_symbols)
+            return (self.id == other.id and self._lib == other._lib
+                    and self._dependent_libs == other._dependent_libs
+                    and self._dependent_files == other._dependent_files
+                    and self._defined_symbols == other._defined_symbols)
 
         else:
             return False
@@ -551,7 +546,7 @@ class NodeExe(NodeInterface):
     def __init__(self, id, name, input=None):
         if isinstance(input, dict):
             should_fail = False
-            for k, v in input.iteritems():
+            for k, v in input.items():
                 try:
                     if isinstance(v, list):
                         setattr(self, k, set(v))
@@ -580,10 +575,12 @@ class NodeExe(NodeInterface):
         return self.id
 
 
-types = {graph_consts.NODE_LIB: NodeLib,
-         graph_consts.NODE_SYM: NodeSymbol,
-         graph_consts.NODE_FILE: NodeFile,
-         graph_consts.NODE_EXE: NodeExe,}
+types = {
+    graph_consts.NODE_LIB: NodeLib,
+    graph_consts.NODE_SYM: NodeSymbol,
+    graph_consts.NODE_FILE: NodeFile,
+    graph_consts.NODE_EXE: NodeExe,
+}
 
 
 def node_factory(id, nodetype, dict_source=None):
diff --git a/site_scons/site_tools/dagger/graph_consts.py b/site_scons/site_tools/dagger/graph_consts.py
index 81fe86d75cd..eae5db9b6c6 100644
--- a/site_scons/site_tools/dagger/graph_consts.py
+++ b/site_scons/site_tools/dagger/graph_consts.py
@@ -1,5 +1,4 @@
 """Constants for use in graph.py and dagger.py"""
-
 """Relationship edge types"""
 LIB_LIB = 1
 LIB_FIL = 2
@@ -17,8 +16,8 @@ NODE_SYM = 2
 NODE_FILE = 3
 NODE_EXE = 4
 
-RELATIONSHIP_TYPES = range(1, 9)
-NODE_TYPES = range(1, 5)
+RELATIONSHIP_TYPES = list(range(1, 9))
+NODE_TYPES = list(range(1, 5))
 
 
 """Error/query codes"""
diff --git a/site_scons/site_tools/dagger/graph_test.py b/site_scons/site_tools/dagger/graph_test.py
index bc84f5868c7..39bdf77ab7c 100644
--- a/site_scons/site_tools/dagger/graph_test.py
+++ b/site_scons/site_tools/dagger/graph_test.py
@@ -5,8 +5,8 @@ from JSON
 
 import json
 import unittest
-import graph
-import graph_consts
+from . import graph
+from . import graph_consts
 
 
 def generate_graph():
@@ -73,26 +73,22 @@ class CustomAssertions:
             raise AssertionError("Nodes not of same type")
 
         if node1.type == graph_consts.NODE_LIB:
-            if (node1._defined_symbols != node2._defined_symbols or
-                    node1._defined_files != node2._defined_files or
-                    node1._dependent_libs != node2._dependent_libs or
-                    node1._dependent_files != node2._dependent_files or
-                    node1._id != node2._id):
+            if (node1._defined_symbols != node2._defined_symbols
+                    or node1._defined_files != node2._defined_files
+                    or node1._dependent_libs != node2._dependent_libs
+                    or node1._dependent_files != node2._dependent_files or node1._id != node2._id):
                 raise AssertionError("Nodes not equal")
 
         elif node1.type == graph_consts.NODE_SYM:
-            if (node1._libs != node2._libs or node1._files != node2._files or
-                    node1._dependent_libs != node2._dependent_libs or
-                    node1._dependent_files != node2._dependent_files or
-                    node1.id != node2.id):
+            if (node1._libs != node2._libs or node1._files != node2._files
+                    or node1._dependent_libs != node2._dependent_libs
+                    or node1._dependent_files != node2._dependent_files or node1.id != node2.id):
                 raise AssertionError("Nodes not equal")
 
         else:
-            if (node1._lib != node2._lib or
-                    node1._dependent_libs != node2._dependent_libs or
-                    node1._dependent_files != node2._dependent_files or
-                    node1.id != node2.id or
-                    node1._defined_symbols != node2._defined_symbols):
+            if (node1._lib != node2._lib or node1._dependent_libs != node2._dependent_libs
+                    or node1._dependent_files != node2._dependent_files or node1.id != node2.id
+                    or node1._defined_symbols != node2._defined_symbols):
                 raise AssertionError("Nodes not equal")
 
 
@@ -104,11 +100,9 @@ class TestGraphMethods(unittest.TestCase, CustomAssertions):
 
         self.from_node_lib = graph.NodeLib("from_node_lib", "from_node_lib")
         self.to_node_lib = graph.NodeLib("to_node_lib", "to_node_lib")
-        self.from_node_file = graph.NodeFile(
-            "from_node_file", "from_node_file")
+        self.from_node_file = graph.NodeFile("from_node_file", "from_node_file")
         self.to_node_file = graph.NodeFile("to_node_file", "to_node_file")
-        self.from_node_sym = graph.NodeSymbol(
-            "from_node_symbol", "from_node_symbol")
+        self.from_node_sym = graph.NodeSymbol("from_node_symbol", "from_node_symbol")
         self.to_node_sym = graph.NodeSymbol("to_node_symbol", "to_node_symbol")
 
         self.g.add_node(self.from_node_lib)
@@ -122,15 +116,15 @@ class TestGraphMethods(unittest.TestCase, CustomAssertions):
         node = graph.NodeLib("test_node", "test_node")
         self.g._nodes = {"test_node": node}
 
-        self.assertEquals(self.g.get_node("test_node"), node)
+        self.assertEqual(self.g.get_node("test_node"), node)
 
-        self.assertEquals(self.g.get_node("missing_node"), None)
+        self.assertEqual(self.g.get_node("missing_node"), None)
 
     def test_add_node(self):
         node = graph.NodeLib("test_node", "test_node")
         self.g.add_node(node)
 
-        self.assertEquals(self.g.get_node("test_node"), node)
+        self.assertEqual(self.g.get_node("test_node"), node)
 
         self.assertRaises(ValueError, self.g.add_node, node)
 
@@ -153,16 +147,16 @@ class TestGraphMethods(unittest.TestCase, CustomAssertions):
         self.g.add_edge(graph_consts.LIB_FIL, self.from_node_lib.id,
                         self.to_node_file.id)
 
-        self.assertEquals(self.g.edges[graph_consts.LIB_LIB][
+        self.assertEqual(self.g.edges[graph_consts.LIB_LIB][
             self.from_node_lib.id], set([self.to_node_lib.id]))
 
-        self.assertEquals(self.g.edges[graph_consts.LIB_SYM][
+        self.assertEqual(self.g.edges[graph_consts.LIB_SYM][
             self.from_node_lib.id], set([self.to_node_sym.id]))
 
-        self.assertEquals(self.g.edges[graph_consts.LIB_FIL][
+        self.assertEqual(self.g.edges[graph_consts.LIB_FIL][
             self.from_node_lib.id], set([self.to_node_file.id]))
 
-        self.assertEquals(self.to_node_lib.dependent_libs,
+        self.assertEqual(self.to_node_lib.dependent_libs,
                           set([self.from_node_lib.id]))
 
     def test_add_edge_files(self):
@@ -173,14 +167,14 @@ class TestGraphMethods(unittest.TestCase, CustomAssertions):
         self.g.add_edge(graph_consts.FIL_LIB, self.from_node_file.id,
                         self.to_node_lib.id)
 
-        self.assertEquals(self.g.edges[graph_consts.FIL_FIL][
+        self.assertEqual(self.g.edges[graph_consts.FIL_FIL][
             self.from_node_file.id], set([self.to_node_file.id]))
-        self.assertEquals(self.g.edges[graph_consts.FIL_SYM][
+        self.assertEqual(self.g.edges[graph_consts.FIL_SYM][
             self.from_node_file.id], set([self.to_node_sym.id]))
-        self.assertEquals(self.g.edges[graph_consts.FIL_LIB][
+        self.assertEqual(self.g.edges[graph_consts.FIL_LIB][
             self.from_node_file.id], set([self.to_node_lib.id]))
 
-        self.assertEquals(self.to_node_file.dependent_files,
+        self.assertEqual(self.to_node_file.dependent_files,
                           set([self.from_node_file.id]))
 
     def test_export_to_json(self):
@@ -188,7 +182,7 @@ class TestGraphMethods(unittest.TestCase, CustomAssertions):
         generated_graph.export_to_json("export_test.json")
         generated = open("export_test.json", "r")
         correct = open("test_graph.json", "r")
-        self.assertEquals(json.load(generated), json.load(correct))
+        self.assertEqual(json.load(generated), json.load(correct))
         generated.close()
         correct.close()
 
@@ -196,7 +190,7 @@ class TestGraphMethods(unittest.TestCase, CustomAssertions):
         graph_fromJSON = graph.Graph("test_graph.json")
         correct_graph = generate_graph()
 
-        for id in graph_fromJSON.nodes.keys():
+        for id in list(graph_fromJSON.nodes.keys()):
             # for some reason, neither
             # assertTrue(graph_fromJSON.get_node(id) == correct_graph.get_node(str(id)))
             # nor assertEquals() seem to call the correct eq method here, hence
@@ -205,7 +199,7 @@ class TestGraphMethods(unittest.TestCase, CustomAssertions):
             self.assertNodeEquals(
                 graph_fromJSON.get_node(id), correct_graph.get_node(id))
 
-        self.assertEquals(graph_fromJSON.edges, correct_graph.edges)
+        self.assertEqual(graph_fromJSON.edges, correct_graph.edges)
 
 
 if __name__ == '__main__':
diff --git a/site_scons/site_tools/distsrc.py b/site_scons/site_tools/distsrc.py
index 861f5d9e2e2..cc72c0655f7 100644
--- a/site_scons/site_tools/distsrc.py
+++ b/site_scons/site_tools/distsrc.py
@@ -20,7 +20,7 @@ import shutil
 import tarfile
 import time
 import zipfile
-import StringIO
+import io
 
 from distutils.spawn import find_executable
 
@@ -28,7 +28,7 @@ __distsrc_callbacks = []
 
 class DistSrcFile:
     def __init__(self, **kwargs):
-        [ setattr(self, key, val) for (key, val) in kwargs.items() ]
+        [ setattr(self, key, val) for (key, val) in list(kwargs.items()) ]
 
     def __str__(self):
         return self.name
@@ -60,6 +60,7 @@ class DistSrcArchive:
     def close(self):
         self.archive_file.close()
 
+
 class DistSrcTarArchive(DistSrcArchive):
     def __iter__(self):
         file_list = self.archive_file.getnames()
@@ -82,7 +83,7 @@ class DistSrcTarArchive(DistSrcArchive):
 
     def append_file_contents(self, filename, file_contents,
             mtime=time.time(),
-            mode=0644,
+            mode=0o644,
             uname="root",
             gname="root"):
         file_metadata = tarfile.TarInfo(name=filename)
@@ -91,7 +92,7 @@ class DistSrcTarArchive(DistSrcArchive):
         file_metadata.uname = uname
         file_metadata.gname = gname
         file_metadata.size = len(file_contents)
-        file_buf = StringIO.StringIO(file_contents)
+        file_buf = io.BytesIO(file_contents.encode('utf-8'))
         if self.archive_mode == 'r':
             self.archive_file.close()
             self.archive_file = tarfile.open(
@@ -105,6 +106,7 @@ class DistSrcTarArchive(DistSrcArchive):
     def append_file(self, filename, localfile):
         self.archive_file.add(localfile, arcname=filename)
 
+
 class DistSrcZipArchive(DistSrcArchive):
     def __iter__(self):
         file_list = self.archive_file.namelist()
@@ -119,7 +121,7 @@ class DistSrcZipArchive(DistSrcArchive):
             name=key,
             size=item_data.file_size,
             mtime=time.mktime(fixed_time),
-            mode=0775 if is_dir else 0664,
+            mode=0o775 if is_dir else 0o664,
             type=tarfile.DIRTYPE if is_dir else tarfile.REGTYPE,
             uid=0,
             gid=0,
@@ -129,7 +131,7 @@ class DistSrcZipArchive(DistSrcArchive):
 
     def append_file_contents(self, filename, file_contents,
             mtime=time.time(),
-            mode=0644,
+            mode=0o644,
             uname="root",
             gname="root"):
         self.archive_file.writestr(filename, file_contents)
@@ -139,7 +141,7 @@ class DistSrcZipArchive(DistSrcArchive):
 
 def build_error_action(msg):
     def error_stub(target=None, source=None, env=None):
-        print msg
+        print(msg)
         env.Exit(1)
     return [ error_stub ]
 
@@ -162,7 +164,7 @@ def distsrc_action_generator(source, target, env, for_signature):
 
     target_ext = str(target[0])[-3:]
     if not target_ext in [ 'zip', 'tar' ]:
-        print "Invalid file format for distsrc. Must be tar or zip file"
+        print("Invalid file format for distsrc. Must be tar or zip file")
         env.Exit(1)
 
     git_cmd = "\"%s\" archive --format %s --output %s --prefix ${MONGO_DIST_SRC_PREFIX} HEAD" % (
@@ -173,14 +175,14 @@ def distsrc_action_generator(source, target, env, for_signature):
         SCons.Action.Action(run_distsrc_callbacks, "Running distsrc callbacks for $TARGET")
     ]
 
+
 def add_callback(env, fn):
     __distsrc_callbacks.append(fn)
 
+
 def generate(env, **kwargs):
     env.AddMethod(add_callback, 'AddDistSrcCallback')
-    env['BUILDERS']['__DISTSRC'] = SCons.Builder.Builder(
-        generator=distsrc_action_generator,
-    )
+    env['BUILDERS']['__DISTSRC'] = SCons.Builder.Builder(generator=distsrc_action_generator, )
 
     def DistSrc(env, target):
         result = env.__DISTSRC(target=target, source=[])
@@ -190,5 +192,6 @@ def generate(env, **kwargs):
 
     env.AddMethod(DistSrc, 'DistSrc')
 
+
 def exists(env):
     return True
diff --git a/site_scons/site_tools/git_decider.py b/site_scons/site_tools/git_decider.py
index cd69de95085..51e6cd54b26 100644
--- a/site_scons/site_tools/git_decider.py
+++ b/site_scons/site_tools/git_decider.py
@@ -12,9 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
 # If available, uses Git metadata to decide whether files are out of date.
 
+
 def generate(env, **kwargs):
 
     # Grab the existing decider functions out of the environment
@@ -47,7 +47,7 @@ def generate(env, **kwargs):
             dependency.get_ninfo().csig = gitInfoForDep
             return False
 
-        if not(hasattr(prev_ni, 'csig')):
+        if not (hasattr(prev_ni, 'csig')):
             prev_ni.csig = gitInfoForDep
 
         result = gitInfoForDep == prev_ni.csig
@@ -60,6 +60,7 @@ def generate(env, **kwargs):
 
     env.Decider(MongoGitDecider)
 
+
 def exists(env):
     try:
         from git import Git
diff --git a/site_scons/site_tools/gziptool.py b/site_scons/site_tools/gziptool.py
index 8419352b481..3142d46cae9 100644
--- a/site_scons/site_tools/gziptool.py
+++ b/site_scons/site_tools/gziptool.py
@@ -18,7 +18,7 @@ import shutil
 
 def GZipAction(target, source, env, **kw):
     dst_gzip = gzip.GzipFile(str(target[0]), 'wb')
-    with open(str(source[0]), 'r') as src_file:
+    with open(str(source[0]), 'rb') as src_file:
         shutil.copyfileobj(src_file, dst_gzip)
     dst_gzip.close()
 
@@ -38,5 +38,6 @@ def generate(env, **kwargs):
 
     env.AddMethod(GZipTool, 'GZip')
 
+
 def exists(env):
     return True
diff --git a/site_scons/site_tools/icecream.py b/site_scons/site_tools/icecream.py
index 9838b633490..003594a7a87 100644
--- a/site_scons/site_tools/icecream.py
+++ b/site_scons/site_tools/icecream.py
@@ -22,6 +22,7 @@ from pkg_resources import parse_version
 
 icecream_version_min = '1.1rc2'
 
+
 def generate(env):
 
     if not exists(env):
@@ -31,14 +32,16 @@ def generate(env):
     env['ICECC'] = env.WhereIs('$ICECC')
 
     if not 'ICERUN' in env:
-         env['ICERUN'] = env.File('$ICECC').File('icerun')
+        env['ICERUN'] = env.File('$ICECC').File('icerun')
 
     # Absoluteify, for parity with ICECC
     env['ICERUN'] = env.WhereIs('$ICERUN')
 
     # We can't handle sanitizer blacklist files, so disable icecc then, and just flow through
     # icerun to prevent slamming the local system with a huge -j value.
-    if any(f.startswith("-fsanitize-blacklist=") for fs in ['CCFLAGS', 'CFLAGS', 'CXXFLAGS'] for f in env[fs]):
+    if any(
+            f.startswith("-fsanitize-blacklist=") for fs in ['CCFLAGS', 'CFLAGS', 'CXXFLAGS']
+            for f in env[fs]):
         env['ICECC'] = '$ICERUN'
 
     # Make CC and CXX absolute paths too. It is better for icecc.
@@ -46,7 +49,7 @@ def generate(env):
     env['CXX'] = env.WhereIs('$CXX')
 
     # Make a predictable name for the toolchain
-    icecc_version_target_filename=env.subst('$CC$CXX').replace('/', '_')
+    icecc_version_target_filename = env.subst('$CC$CXX').replace('/', '_')
     icecc_version = env.Dir('$BUILD_ROOT/scons/icecc').File(icecc_version_target_filename)
 
     # Make an isolated environment so that our setting of ICECC_VERSION in the environment
@@ -63,12 +66,9 @@ def generate(env):
         env['ENV']['ICECC_CLANG_REMOTE_CPP'] = 1
     else:
         toolchain = toolchain_env.Command(
-            target=icecc_version,
-            source=['$ICECC_CREATE_ENV', '$CC', '$CXX'],
-            action=[
+            target=icecc_version, source=['$ICECC_CREATE_ENV', '$CC', '$CXX'], action=[
                 "${SOURCES[0]} --gcc ${SOURCES[1].abspath} ${SOURCES[2].abspath} $TARGET",
-            ]
-        )
+            ])
         env.AppendUnique(CCFLAGS=['-fdirectives-only'])
 
     # Add ICECC_VERSION to the environment, pointed at the generated
@@ -99,7 +99,7 @@ def generate(env):
     suffixes = _CSuffixes + _CXXSuffixes
     for object_builder in SCons.Tool.createObjBuilders(env):
         emitterdict = object_builder.builder.emitter
-        for suffix in emitterdict.iterkeys():
+        for suffix in emitterdict.keys():
             if not suffix in suffixes:
                 continue
             base = emitterdict[suffix]
@@ -128,6 +128,7 @@ def generate(env):
     # env['ENV']['ICECC_DEBUG'] = 'debug'
     # env['ENV']['ICECC_LOGFILE'] = 'icecc.log'
 
+
 def exists(env):
 
     icecc = env.get('ICECC', False)
@@ -135,10 +136,9 @@ def exists(env):
         return False
     icecc = env.WhereIs(icecc)
 
-    pipe = SCons.Action._subproc(env, SCons.Util.CLVar(icecc) + ['--version'],
-                                 stdin = 'devnull',
-                                 stderr = 'devnull',
-                                 stdout = subprocess.PIPE)
+    pipe = SCons.Action._subproc(env,
+                                 SCons.Util.CLVar(icecc) + ['--version'], stdin='devnull',
+                                 stderr='devnull', stdout=subprocess.PIPE, text=True)
 
     if pipe.wait() != 0:
         return False
diff --git a/site_scons/site_tools/idl_tool.py b/site_scons/site_tools/idl_tool.py
index c7f64293f5d..58873b576d0 100755
--- a/site_scons/site_tools/idl_tool.py
+++ b/site_scons/site_tools/idl_tool.py
@@ -21,6 +21,7 @@ import sys
 
 import SCons
 
+
 def idlc_emitter(target, source, env):
     """For each input IDL file, the tool produces a .cpp and .h file."""
     first_source = str(source[0])
@@ -44,9 +45,9 @@ def idl_scanner(node, env, path):
     # Use the import scanner mode of the IDL compiler to file imported files
     cmd = [sys.executable, "buildscripts/idl/idlc.py",  '--include','src', str(node), '--write-dependencies']
     try:
-        deps_str = subprocess.check_output(cmd)
+        deps_str = subprocess.check_output(cmd).decode('utf-8')
     except subprocess.CalledProcessError as e:
-        print("IDLC ERROR: %s" % (e.output) )
+        print(("IDLC ERROR: %s" % (e.output) ))
         raise
 
     deps_list = deps_str.splitlines()
@@ -61,29 +62,26 @@ def idl_scanner(node, env, path):
 idl_scanner = SCons.Scanner.Scanner(function=idl_scanner, skeys=['.idl'])
 
 # TODO: create a scanner for imports when imports are implemented
-IDLCBuilder = SCons.Builder.Builder(
-    action=IDLCAction,
-    emitter=idlc_emitter,
-    srcsuffx=".idl",
-    suffix=".cpp",
-    source_scanner = idl_scanner
-    )
+IDLCBuilder = SCons.Builder.Builder(action=IDLCAction, emitter=idlc_emitter, srcsuffx=".idl",
+                                    suffix=".cpp", source_scanner=idl_scanner)
 
 
 def generate(env):
     bld = IDLCBuilder
 
-    env.Append(SCANNERS = idl_scanner)
+    env.Append(SCANNERS=idl_scanner)
 
     env['BUILDERS']['Idlc'] = bld
 
     env['IDLC'] = sys.executable + " buildscripts/idl/idlc.py"
     env['IDLCFLAGS'] = ''
     base_dir = env.subst('$BUILD_ROOT/$VARIANT_DIR').replace("#", "")
-    env['IDLCCOM'] = '$IDLC --include src --base_dir %s --target_arch $TARGET_ARCH --header ${TARGETS[1]} --output ${TARGETS[0]} $SOURCES ' % (base_dir)
+    env['IDLCCOM'] = '$IDLC --include src --base_dir %s --target_arch $TARGET_ARCH --header ${TARGETS[1]} --output ${TARGETS[0]} $SOURCES ' % (
+        base_dir)
     env['IDLCSUFFIX'] = '.idl'
 
     env['IDL_HAS_INLINE_DEPENDENCIES'] = True
 
+
 def exists(env):
     return True
diff --git a/site_scons/site_tools/incremental_link.py b/site_scons/site_tools/incremental_link.py
index cf74ef9674c..31f16a482da 100644
--- a/site_scons/site_tools/incremental_link.py
+++ b/site_scons/site_tools/incremental_link.py
@@ -14,10 +14,12 @@
 
 import SCons
 
+
 def _tag_as_precious(target, source, env):
     env.Precious(target)
     return target, source
 
+
 def generate(env):
     builders = env['BUILDERS']
     for builder in ('Program', 'SharedLibrary', 'LoadableModule'):
@@ -27,6 +29,7 @@ def generate(env):
             _tag_as_precious,
         ])
 
+
 def exists(env):
     # By default, the windows linker is incremental, so unless
     # overridden in the environment with /INCREMENTAL:NO, the tool is
diff --git a/site_scons/site_tools/jsheader.py b/site_scons/site_tools/jsheader.py
index cb418506200..4c2765b7108 100644
--- a/site_scons/site_tools/jsheader.py
+++ b/site_scons/site_tools/jsheader.py
@@ -1,13 +1,14 @@
 from SCons.Script import Action
 
+
 def jsToH(env, target, source):
-    return env.Command(
-        target=target,
-        source=['#site_scons/site_tools/jstoh.py'] + source,
-        action=Action('$PYTHON ${SOURCES[0]} $TARGET ${SOURCES[1:]}'))
+    return env.Command(target=target, source=['#site_scons/site_tools/jstoh.py'] + source,
+                       action=Action('$PYTHON ${SOURCES[0]} $TARGET ${SOURCES[1:]}'))
+
 
 def generate(env, **kw):
     env.AddMethod(jsToH, 'JSHeader')
 
+
 def exists(env):
     return True
diff --git a/site_scons/site_tools/jstoh.py b/site_scons/site_tools/jstoh.py
index 26eb6cbbf24..50c0b66cf32 100644
--- a/site_scons/site_tools/jstoh.py
+++ b/site_scons/site_tools/jstoh.py
@@ -39,7 +39,7 @@ def jsToHeader(target, source):
 
     text = '\n'.join(h)
 
-    with open(outFile, 'wb') as out:
+    with open(outFile, 'w') as out:
         try:
             out.write(text)
         finally:
@@ -48,7 +48,7 @@ def jsToHeader(target, source):
 
 if __name__ == "__main__":
     if len(sys.argv) < 3:
-        print "Must specify [target] [source] "
+        print("Must specify [target] [source] ")
         sys.exit(1)
 
     jsToHeader(sys.argv[1], sys.argv[2:])
diff --git a/site_scons/site_tools/libtool.py b/site_scons/site_tools/libtool.py
index 84a646ed066..a098d722fe8 100644
--- a/site_scons/site_tools/libtool.py
+++ b/site_scons/site_tools/libtool.py
@@ -1,5 +1,6 @@
 import SCons
 
+
 def generate(env):
 
     env['AR'] = 'libtool'
@@ -13,5 +14,6 @@ def generate(env):
     env['RANLIBCOM'] = noop_action
     env['RANLIBCOMSTR'] = 'Skipping ranlib for libtool generated target $TARGET'
 
+
 def exists(env):
     return env.detect('libtool')
diff --git a/site_scons/site_tools/mongo_benchmark.py b/site_scons/site_tools/mongo_benchmark.py
index 2064516aa1f..d9c6a02f91e 100644
--- a/site_scons/site_tools/mongo_benchmark.py
+++ b/site_scons/site_tools/mongo_benchmark.py
@@ -11,10 +11,10 @@ def register_benchmark(env, test):
     env.Alias('$BENCHMARK_ALIAS', test)
 
 def benchmark_list_builder_action(env, target, source):
-    ofile = open(str(target[0]), 'wb')
+    ofile = open(str(target[0]), 'w')
     try:
         for s in _benchmarks:
-            print '\t' + str(s)
+            print('\t' + str(s))
             ofile.write('%s\n' % s)
     finally:
         ofile.close()
@@ -40,9 +40,10 @@ def build_benchmark(env, target, source, **kwargs):
         bmEnv.Install("#/build/benchmark/", result[0])
     return result
 
+
 def generate(env):
     env.Command('$BENCHMARK_LIST', env.Value(_benchmarks),
-            Action(benchmark_list_builder_action, "Generating $TARGET"))
+                Action(benchmark_list_builder_action, "Generating $TARGET"))
     env.AddMethod(register_benchmark, 'RegisterBenchmark')
     env.AddMethod(build_benchmark, 'Benchmark')
     env.Alias('$BENCHMARK_ALIAS', '$BENCHMARK_LIST')
diff --git a/site_scons/site_tools/mongo_integrationtest.py b/site_scons/site_tools/mongo_integrationtest.py
index 0ced90c9493..8e830958960 100644
--- a/site_scons/site_tools/mongo_integrationtest.py
+++ b/site_scons/site_tools/mongo_integrationtest.py
@@ -12,10 +12,10 @@ def register_integration_test(env, test):
     env.Alias('$INTEGRATION_TEST_ALIAS', installed_test)
 
 def integration_test_list_builder_action(env, target, source):
-    ofile = open(str(target[0]), 'wb')
+    ofile = open(str(target[0]), 'w')
     try:
         for s in _integration_tests:
-            print '\t' + str(s)
+            print('\t' + str(s))
             ofile.write('%s\n' % s)
     finally:
         ofile.close()
@@ -31,9 +31,10 @@ def build_cpp_integration_test(env, target, source, **kwargs):
     env.RegisterIntegrationTest(result[0])
     return result
 
+
 def generate(env):
     env.Command('$INTEGRATION_TEST_LIST', env.Value(_integration_tests),
-            Action(integration_test_list_builder_action, "Generating $TARGET"))
+                Action(integration_test_list_builder_action, "Generating $TARGET"))
     env.AddMethod(register_integration_test, 'RegisterIntegrationTest')
     env.AddMethod(build_cpp_integration_test, 'CppIntegrationTest')
     env.Alias('$INTEGRATION_TEST_ALIAS', '$INTEGRATION_TEST_LIST')
diff --git a/site_scons/site_tools/mongo_unittest.py b/site_scons/site_tools/mongo_unittest.py
index 2ad0f51bfd0..938be7f9741 100644
--- a/site_scons/site_tools/mongo_unittest.py
+++ b/site_scons/site_tools/mongo_unittest.py
@@ -11,10 +11,10 @@ def register_unit_test(env, test):
     env.Alias('$UNITTEST_ALIAS', test)
 
 def unit_test_list_builder_action(env, target, source):
-    ofile = open(str(target[0]), 'wb')
+    ofile = open(str(target[0]), 'w')
     try:
         for s in _unittests:
-            print '\t' + str(s)
+            print('\t' + str(s))
             ofile.write('%s\n' % s)
     finally:
         ofile.close()
@@ -33,9 +33,10 @@ def build_cpp_unit_test(env, target, source, **kwargs):
         env.Install("#/build/unittests/", result[0])
     return result
 
+
 def generate(env):
     env.Command('$UNITTEST_LIST', env.Value(_unittests),
-            Action(unit_test_list_builder_action, "Generating $TARGET"))
+                Action(unit_test_list_builder_action, "Generating $TARGET"))
     env.AddMethod(register_unit_test, 'RegisterUnitTest')
     env.AddMethod(build_cpp_unit_test, 'CppUnitTest')
     env.Alias('$UNITTEST_ALIAS', '$UNITTEST_LIST')
diff --git a/site_scons/site_tools/separate_debug.py b/site_scons/site_tools/separate_debug.py
index 3edd50518e1..6e78796244b 100644
--- a/site_scons/site_tools/separate_debug.py
+++ b/site_scons/site_tools/separate_debug.py
@@ -14,6 +14,7 @@
 
 import SCons
 
+
 def _update_builder(env, builder, bitcode):
 
     old_scanner = builder.target_scanner
@@ -25,7 +26,8 @@ def _update_builder(env, builder, bitcode):
         if origin:
             origin_results = old_scanner(origin, env, path)
             for origin_result in origin_results:
-                origin_result_debug_file = getattr(origin_result.attributes, "separate_debug_file", None)
+                origin_result_debug_file = getattr(origin_result.attributes, "separate_debug_file",
+                                                   None)
                 if origin_result_debug_file:
                     results.append(origin_result_debug_file)
         # TODO: Do we need to do the same sort of drag along for bcsymbolmap files?
@@ -52,38 +54,26 @@ def _update_builder(env, builder, bitcode):
             base_action.list.append(
                 SCons.Action.Action(
                     "dsymutil $TARGET --symbol-map=${TARGET}.bcsymbolmap -o ${TARGET}.dSYM",
-                    "Generating debug info for $TARGET into ${TARGET}.dSYM"
-                )
-            )
+                    "Generating debug info for $TARGET into ${TARGET}.dSYM"))
 
         else:
             base_action.list.append(
-                SCons.Action.Action(
-                    "dsymutil $TARGET -o ${TARGET}.dSYM",
-                    "Generating debug info for $TARGET into ${TARGET}.dSYM"
-                )
-            )
-        base_action.list.append(
-            SCons.Action.Action(
-                "strip -Sx ${TARGET}",
-                "Stripping ${TARGET}"
-            )
-        )
+                SCons.Action.Action("dsymutil $TARGET -o ${TARGET}.dSYM",
+                                    "Generating debug info for $TARGET into ${TARGET}.dSYM"))
+        base_action.list.append(SCons.Action.Action("strip -Sx ${TARGET}", "Stripping ${TARGET}"))
     elif env.TargetOSIs('posix'):
         base_action.list.extend([
-            SCons.Action.Action(
-                "${OBJCOPY} --only-keep-debug $TARGET ${TARGET}.debug",
-                "Generating debug info for $TARGET into ${TARGET}.debug"
-            ),
+            SCons.Action.Action("${OBJCOPY} --only-keep-debug $TARGET ${TARGET}.debug",
+                                "Generating debug info for $TARGET into ${TARGET}.debug"),
             SCons.Action.Action(
                 "${OBJCOPY} --strip-debug --add-gnu-debuglink ${TARGET}.debug ${TARGET}",
-                "Stripping debug info from ${TARGET} and adding .gnu.debuglink to ${TARGET}.debug"
-            ),
+                "Stripping debug info from ${TARGET} and adding .gnu.debuglink to ${TARGET}.debug"),
         ])
     else:
         pass
 
     base_emitter = builder.emitter
+
     def new_emitter(target, source, env):
 
         bitcode_file = None
@@ -111,6 +101,7 @@ def _update_builder(env, builder, bitcode):
     new_emitter = SCons.Builder.ListEmitter([base_emitter, new_emitter])
     builder.emitter = new_emitter
 
+
 def generate(env):
     if not exists(env):
         return
@@ -132,12 +123,12 @@ def generate(env):
             "-Wl,-bitcode_symbol_map,${TARGET}.bcsymbolmap",
         ])
 
-
     # TODO: For now, not doing this for programs. Need to update
     # auto_install_binaries to understand to install the debug symbol
     # for target X to the same target location as X.
     for builder in ['SharedLibrary', 'LoadableModule']:
         _update_builder(env, env['BUILDERS'][builder], bitcode)
 
+
 def exists(env):
     return True
diff --git a/site_scons/site_tools/split_dwarf.py b/site_scons/site_tools/split_dwarf.py
index 95130c9e9a3..c57b9e96822 100644
--- a/site_scons/site_tools/split_dwarf.py
+++ b/site_scons/site_tools/split_dwarf.py
@@ -26,6 +26,7 @@ _CXXSuffixes = ['.cpp', '.cc', '.cxx', '.c++', '.C++']
 if SCons.Util.case_sensitive_suffixes('.c', '.C'):
     _CXXSuffixes.append('.C')
 
+
 def _dwo_emitter(target, source, env):
     new_targets = []
     for t in target:
@@ -40,6 +41,7 @@ def _dwo_emitter(target, source, env):
     targets = target + new_targets
     return (targets, source)
 
+
 def generate(env):
     suffixes = []
     if _splitDwarfFlag in env['CCFLAGS']:
@@ -52,7 +54,7 @@ def generate(env):
 
     for object_builder in SCons.Tool.createObjBuilders(env):
         emitterdict = object_builder.builder.emitter
-        for suffix in emitterdict.iterkeys():
+        for suffix in emitterdict.keys():
             if not suffix in suffixes:
                 continue
             base = emitterdict[suffix]
@@ -61,5 +63,6 @@ def generate(env):
                 _dwo_emitter,
             ])
 
+
 def exists(env):
     return any(_splitDwarfFlag in env[f] for f in ['CCFLAGS', 'CFLAGS', 'CXXFLAGS'])
diff --git a/site_scons/site_tools/thin_archive.py b/site_scons/site_tools/thin_archive.py
index 15357874438..b4b5b91ad5e 100644
--- a/site_scons/site_tools/thin_archive.py
+++ b/site_scons/site_tools/thin_archive.py
@@ -17,6 +17,7 @@ import SCons
 import re
 import subprocess
 
+
 def exists(env):
     if not 'AR' in env:
         return False
@@ -30,10 +31,9 @@ def exists(env):
     if not "rc" in env['ARFLAGS']:
         return False
 
-    pipe = SCons.Action._subproc(env, SCons.Util.CLVar(ar) + ['--version'],
-                                 stdin = 'devnull',
-                                 stderr = 'devnull',
-                                 stdout = subprocess.PIPE)
+    pipe = SCons.Action._subproc(env,
+                                 SCons.Util.CLVar(ar) + ['--version'], stdin='devnull',
+                                 stderr='devnull', stdout=subprocess.PIPE)
     if pipe.wait() != 0:
         return False
 
@@ -41,7 +41,7 @@ def exists(env):
     for line in pipe.stdout:
         if found:
             continue  # consume all data
-        found = re.search(r'^GNU ar|^LLVM', line)
+        found = re.search(r'^GNU ar|^LLVM', line.decode('utf-8'))
 
     return bool(found)
 
@@ -56,6 +56,7 @@ def _add_emitter(builder):
     new_emitter = SCons.Builder.ListEmitter([base_emitter, new_emitter])
     builder.emitter = new_emitter
 
+
 def _add_scanner(builder):
     old_scanner = builder.target_scanner
     path_function = old_scanner.path_function
@@ -69,13 +70,16 @@ def _add_scanner(builder):
                 new_results.extend(base.children())
         return new_results
 
-    builder.target_scanner = SCons.Scanner.Scanner(function=new_scanner, path_function=path_function)
+    builder.target_scanner = SCons.Scanner.Scanner(function=new_scanner,
+                                                   path_function=path_function)
+
 
 def generate(env):
     if not exists(env):
         return
 
-    env['ARFLAGS'] = SCons.Util.CLVar([arflag if arflag != "rc" else "rcsTD" for arflag in env['ARFLAGS']])
+    env['ARFLAGS'] = SCons.Util.CLVar(
+        [arflag if arflag != "rc" else "rcsTD" for arflag in env['ARFLAGS']])
 
     def noop_action(env, target, source):
         pass
diff --git a/site_scons/site_tools/xcode.py b/site_scons/site_tools/xcode.py
index 9ec68c35470..5ddebb2e003 100644
--- a/site_scons/site_tools/xcode.py
+++ b/site_scons/site_tools/xcode.py
@@ -9,4 +9,4 @@ def generate(env):
 
     if 'DEVELOPER_DIR' in os.environ:
         env['ENV']['DEVELOPER_DIR'] = os.environ['DEVELOPER_DIR']
-        print "NOTE: Xcode detected; propagating DEVELOPER_DIR from shell environment to subcommands"
+        print("NOTE: Xcode detected; propagating DEVELOPER_DIR from shell environment to subcommands")