--- a/client.mk
+++ b/client.mk
@@ -53,20 +53,16 @@ MOZCONFIG_CONTENT := $(subst ||,$(CR),$(
 include $(OBJDIR)/.mozconfig-client-mk
 
 # As '||' was used as a newline separator, it means it's not occurring in
 # lines themselves. It can thus safely be used to replaces normal spaces,
 # to then replace newlines with normal spaces. This allows to get a list
 # of mozconfig output lines.
 MOZCONFIG_OUT_LINES := $(subst $(CR), ,$(subst $(NULL) $(NULL),||,$(MOZCONFIG_CONTENT)))
 
-ifdef AUTOCLOBBER
-export AUTOCLOBBER=1
-endif
-
 ifdef MOZ_PARALLEL_BUILD
   MOZ_MAKE_FLAGS := $(filter-out -j%,$(MOZ_MAKE_FLAGS))
   MOZ_MAKE_FLAGS += -j$(MOZ_PARALLEL_BUILD)
 endif
 
 # Automatically add -jN to make flags if not defined. N defaults to number of cores.
 ifeq (,$(findstring -j,$(MOZ_MAKE_FLAGS)))
   cores=$(shell $(PYTHON) -c 'import multiprocessing; print(multiprocessing.cpu_count())')
@@ -96,17 +92,17 @@ build::
 
 ifndef MACH
 $(error client.mk must be used via `mach`. Try running \
 `./mach $(firstword $(MAKECMDGOALS) $(.DEFAULT_GOAL))`)
 endif
 
 # For now, only output "export" lines and lines containing UPLOAD_EXTRA_FILES.
 MOZCONFIG_MK_LINES := $(filter export||% UPLOAD_EXTRA_FILES% %UPLOAD_EXTRA_FILES%,$(MOZCONFIG_OUT_LINES))
-$(OBJDIR)/.mozconfig.mk: $(TOPSRCDIR)/client.mk $(FOUND_MOZCONFIG) $(OBJDIR)/CLOBBER
+$(OBJDIR)/.mozconfig.mk: $(TOPSRCDIR)/client.mk $(FOUND_MOZCONFIG)
 	$(if $(MOZCONFIG_MK_LINES),( $(foreach line,$(MOZCONFIG_MK_LINES), echo '$(subst ||, ,$(line))';) )) > $@
 
 # Include that makefile so that it is created. This should not actually change
 # the environment since MOZCONFIG_CONTENT, which MOZCONFIG_OUT_LINES derives
 # from, has already been eval'ed.
 include $(OBJDIR)/.mozconfig.mk
 
 # Print out any options loaded from mozconfig.
@@ -148,17 +144,16 @@ EXTRA_CONFIG_DEPS := \
 $(CONFIGURES): %: %.in $(EXTRA_CONFIG_DEPS)
 	@echo Generating $@
 	cp -f $< $@
 	chmod +x $@
 
 CONFIG_STATUS_DEPS := \
   $(wildcard $(TOPSRCDIR)/*/confvars.sh) \
   $(CONFIGURES) \
-  $(TOPSRCDIR)/CLOBBER \
   $(TOPSRCDIR)/nsprpub/configure \
   $(TOPSRCDIR)/config/milestone.txt \
   $(TOPSRCDIR)/browser/config/version.txt \
   $(TOPSRCDIR)/browser/config/version_display.txt \
   $(TOPSRCDIR)/build/virtualenv_packages.txt \
   $(TOPSRCDIR)/python/mozbuild/mozbuild/virtualenv.py \
   $(TOPSRCDIR)/testing/mozbase/packages.txt \
   $(OBJDIR)/.mozconfig.json \
@@ -176,24 +171,19 @@ CONFIGURE_ENV_ARGS += \
 #   $(TOPSRCDIR) will set @srcdir@ to "."; otherwise, it is set to the full
 #   path of $(TOPSRCDIR).
 ifeq ($(TOPSRCDIR),$(OBJDIR))
   CONFIGURE = ./configure
 else
   CONFIGURE = $(TOPSRCDIR)/configure
 endif
 
-$(OBJDIR)/CLOBBER: $(TOPSRCDIR)/CLOBBER
-	$(PYTHON) $(TOPSRCDIR)/config/pythonpath.py -I $(TOPSRCDIR)/testing/mozbase/mozfile \
-	    $(TOPSRCDIR)/python/mozbuild/mozbuild/controller/clobber.py $(TOPSRCDIR) $(OBJDIR)
-
 configure-files: $(CONFIGURES)
 
 configure-preqs = \
-  $(OBJDIR)/CLOBBER \
   configure-files \
   save-mozconfig \
   $(OBJDIR)/.mozconfig.json \
   $(NULL)
 
 CREATE_MOZCONFIG_JSON = $(shell $(TOPSRCDIR)/mach environment --format=json -o $(OBJDIR)/.mozconfig.json)
 # Force CREATE_MOZCONFIG_JSON above to be resolved, without side effects in
 # case the result is non empty, and allowing an override on the make command

--- a/python/mozbuild/mozbuild/controller/building.py
+++ b/python/mozbuild/mozbuild/controller/building.py
@@ -1,15 +1,16 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from __future__ import absolute_import, unicode_literals
 
 import getpass
+import io
 import json
 import logging
 import os
 import subprocess
 import sys
 import time
 import which
 
@@ -27,16 +28,19 @@ try:
 except Exception:
     psutil = None
 
 from mach.mixin.logging import LoggingMixin
 from mozsystemmonitor.resourcemonitor import SystemResourceMonitor
 
 import mozpack.path as mozpath
 
+from .clobber import (
+    Clobberer,
+)
 from ..base import (
     BuildEnvironmentNotFoundException,
     MozbuildObject,
 )
 from ..backend import (
     get_backend_class,
 )
 from ..testing import (
@@ -1324,16 +1328,20 @@ class BuildDriver(MozbuildObject):
     def _run_client_mk(self, target=None, line_handler=None, jobs=0,
                        verbose=None, keep_going=False, append_env=None):
         append_env = dict(append_env or {})
         append_env['TOPSRCDIR'] = self.topsrcdir
 
         append_env['CONFIG_GUESS'] = self.resolve_config_guess()
 
         mozconfig = self.mozconfig
+
+        if self._check_clobber(mozconfig, os.environ):
+            return 1
+
         mozconfig_client_mk = os.path.join(self.topobjdir,
                                            '.mozconfig-client-mk')
         with FileAvoidWrite(mozconfig_client_mk) as fh:
             for arg in mozconfig['make_extra'] or []:
                 fh.write(arg)
                 fh.write(b'\n')
             if mozconfig['make_flags']:
                 fh.write(b'MOZ_MAKE_FLAGS=%s\n' % b' '.join(mozconfig['make_flags']))
@@ -1354,8 +1362,37 @@ class BuildDriver(MozbuildObject):
                               print_directory=False,
                               target=target,
                               line_handler=line_handler,
                               log=False,
                               num_jobs=jobs,
                               silent=not verbose,
                               keep_going=keep_going,
                               append_env=append_env)
+
+    def _check_clobber(self, mozconfig, env):
+        auto_clobber = any([
+            env.get('AUTOCLOBBER', False),
+            (mozconfig['env'] or {}).get('added', {}).get('AUTOCLOBBER', False),
+            'AUTOCLOBBER=1' in (mozconfig['make_extra'] or []),
+        ])
+
+        clobberer = Clobberer(self.topsrcdir, self.topobjdir)
+        clobber_output = io.BytesIO()
+        res = clobberer.maybe_do_clobber(os.getcwd(), auto_clobber,
+                                         clobber_output)
+        clobber_output.seek(0)
+        for line in clobber_output.readlines():
+            self.log(logging.WARNING, 'clobber',
+                     {'msg': line.rstrip()}, '{msg}')
+
+        clobber_required, clobber_performed, clobber_message = res
+        if not clobber_required or clobber_performed:
+            if clobber_performed and env.get('TINDERBOX_OUTPUT'):
+                self.log(logging.WARNING, 'clobber',
+                         {'msg': 'TinderboxPrint: auto clobber'}, '{msg}')
+        else:
+            for line in clobber_message.splitlines():
+                self.log(logging.WARNING, 'clobber',
+                         {'msg': line.rstrip()}, '{msg}')
+            return True
+
+        return False

--- a/python/mozbuild/mozbuild/controller/clobber.py
+++ b/python/mozbuild/mozbuild/controller/clobber.py
@@ -199,39 +199,8 @@ class Clobberer(object):
             return True, False, self._message(
                 'Error when automatically clobbering: ' + str(error))
 
     def _message(self, reason):
         lines = [' ' + line for line in self.clobber_cause()]
 
         return CLOBBER_MESSAGE.format(clobber_reason='\n'.join(lines),
             no_reason='  ' + reason, clobber_file=self.obj_clobber)
-
-
-def main(args, env, cwd, fh=sys.stderr):
-    if len(args) != 2:
-        print('Usage: clobber.py topsrcdir topobjdir', file=fh)
-        return 1
-
-    topsrcdir, topobjdir = args
-
-    if not os.path.isabs(topsrcdir):
-        topsrcdir = os.path.abspath(topsrcdir)
-
-    if not os.path.isabs(topobjdir):
-        topobjdir = os.path.abspath(topobjdir)
-
-    auto = True if env.get('AUTOCLOBBER', False) else False
-    clobber = Clobberer(topsrcdir, topobjdir)
-    required, performed, message = clobber.maybe_do_clobber(cwd, auto, fh)
-
-    if not required or performed:
-        if performed and env.get('TINDERBOX_OUTPUT'):
-            print('TinderboxPrint: auto clobber', file=fh)
-        return 0
-
-    print(message, file=fh)
-    return 1
-
-
-if __name__ == '__main__':
-    sys.exit(main(sys.argv[1:], os.environ, os.getcwd(), sys.stdout))
-

--- a/python/mozbuild/mozbuild/test/controller/test_clobber.py
+++ b/python/mozbuild/mozbuild/test/controller/test_clobber.py
@@ -8,18 +8,25 @@ import os
 import shutil
 import tempfile
 import unittest
 
 from StringIO import StringIO
 
 from mozunit import main
 
-from mozbuild.controller.clobber import Clobberer
-from mozbuild.controller.clobber import main as clobber
+from mozbuild.base import (
+    MozbuildObject,
+)
+from mozbuild.controller.building import (
+    BuildDriver,
+)
+from mozbuild.controller.clobber import (
+    Clobberer,
+)
 
 
 class TestClobberer(unittest.TestCase):
     def setUp(self):
         self._temp_dirs = []
 
         return unittest.TestCase.setUp(self)
 
@@ -188,26 +195,26 @@ class TestClobberer(unittest.TestCase):
         old_time = os.path.getmtime(os.path.join(topsrcdir, 'CLOBBER')) - 60
         os.utime(obj_clobber, (old_time, old_time))
 
         # Check auto clobber is off by default
         env = dict(os.environ)
         if env.get('AUTOCLOBBER', False):
             del env['AUTOCLOBBER']
 
-        s = StringIO()
-        status = clobber([topsrcdir, topobjdir], env, os.getcwd(), s)
-        self.assertEqual(status, 1)
-        self.assertIn('Automatic clobbering is not enabled', s.getvalue())
+        mbo = MozbuildObject(topsrcdir, None, None, topobjdir)
+        build = mbo._spawn(BuildDriver)
+
+        status = build._check_clobber(build.mozconfig, env)
+
+        self.assertEqual(status, True)
         self.assertTrue(os.path.exists(dummy_file))
 
         # Check auto clobber opt-in works
         env['AUTOCLOBBER'] = '1'
 
-        s = StringIO()
-        status = clobber([topsrcdir, topobjdir], env, os.getcwd(), s)
-        self.assertEqual(status, 0)
-        self.assertIn('Successfully completed auto clobber', s.getvalue())
+        status = build._check_clobber(build.mozconfig, env)
+        self.assertFalse(status)
         self.assertFalse(os.path.exists(dummy_file))
 
 
 if __name__ == '__main__':
     main()