--- a/testing/mozharness/configs/builds/releng_base_android_64_builds.py
+++ b/testing/mozharness/configs/builds/releng_base_android_64_builds.py
@@ -1,17 +1,16 @@
 import os
 
 config = {
     #########################################################################
     ######## ANDROID GENERIC CONFIG KEYS/VAlUES
 
     # note: overridden by MOZHARNESS_ACTIONS in TaskCluster tasks
     'default_actions': [
-        'clobber',
         'build',
         'multi-l10n',
         'update',  # decided by query_is_nightly()
     ],
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     'max_build_output_timeout': 0,
     # decides whether we want to use moz_sign_cmd in env
     'secret_files': [

--- a/testing/mozharness/configs/builds/releng_base_mac_64_cross_builds.py
+++ b/testing/mozharness/configs/builds/releng_base_mac_64_cross_builds.py
@@ -1,17 +1,16 @@
 import os
 
 config = {
     #########################################################################
     ######## MACOSX CROSS GENERIC CONFIG KEYS/VAlUES
 
     # note: overridden by MOZHARNESS_ACTIONS in TaskCluster tasks
     'default_actions': [
-        'clobber',
         'build',
         'update',  # decided by query_is_nightly()
     ],
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'secret_files': [
         {'filename': '/builds/gapi.data',
          'secret_name': 'project/releng/gecko/build/level-%(scm-level)s/gapi.data',

--- a/testing/mozharness/configs/builds/releng_sub_linux_configs/32_artifact.py
+++ b/testing/mozharness/configs/builds/releng_sub_linux_configs/32_artifact.py
@@ -5,17 +5,16 @@ config = {
     ######## LINUX GENERIC CONFIG KEYS/VAlUES
     # if you are updating this with custom 32 bit keys/values please add them
     # below under the '32 bit specific' code block otherwise, update in this
     # code block and also make sure this is synced with
     # releng_base_linux_64_builds.py
 
     # note: overridden by MOZHARNESS_ACTIONS in TaskCluster tasks
     'default_actions': [
-        'clobber',
         'build',
     ],
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'vcs_share_base': '/builds/hg-shared',
     # allows triggering of dependent jobs when --artifact try syntax is detected
     'perfherder_extra_options': ['artifact'],
     #########################################################################

--- a/testing/mozharness/configs/builds/releng_sub_linux_configs/32_debug_artifact.py
+++ b/testing/mozharness/configs/builds/releng_sub_linux_configs/32_debug_artifact.py
@@ -5,17 +5,16 @@ config = {
     ######## LINUX GENERIC CONFIG KEYS/VAlUES
     # if you are updating this with custom 32 bit keys/values please add them
     # below under the '32 bit specific' code block otherwise, update in this
     # code block and also make sure this is synced with
     # releng_base_linux_64_builds.py
 
     # note: overridden by MOZHARNESS_ACTIONS in TaskCluster tasks
     'default_actions': [
-        'clobber',
         'build',
     ],
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'vcs_share_base': '/builds/hg-shared',
     # debug specific
     'debug_build': True,
     # allows triggering of test jobs when --artifact try syntax is detected

--- a/testing/mozharness/configs/builds/releng_sub_linux_configs/64_artifact.py
+++ b/testing/mozharness/configs/builds/releng_sub_linux_configs/64_artifact.py
@@ -1,14 +1,13 @@
 import os
 
 config = {
     # note: overridden by MOZHARNESS_ACTIONS in TaskCluster tasks
     'default_actions': [
-        'clobber',
         'build',
     ],
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'secret_files': [
         {'filename': '/builds/gapi.data',
          'secret_name': 'project/releng/gecko/build/level-%(scm-level)s/gapi.data',
          'min_scm_level': 1},

--- a/testing/mozharness/configs/builds/releng_sub_linux_configs/64_debug_artifact.py
+++ b/testing/mozharness/configs/builds/releng_sub_linux_configs/64_debug_artifact.py
@@ -1,14 +1,13 @@
 import os
 
 config = {
     # note: overridden by MOZHARNESS_ACTIONS in TaskCluster tasks
     'default_actions': [
-        'clobber',
         'build',
     ],
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     'vcs_share_base': '/builds/hg-shared',
     # debug specific
     'debug_build': True,
     # decides whether we want to use moz_sign_cmd in env
     # allows triggering of test jobs when --artifact try syntax is detected

--- a/testing/mozharness/configs/builds/releng_sub_mac_configs/64_artifact.py
+++ b/testing/mozharness/configs/builds/releng_sub_mac_configs/64_artifact.py
@@ -1,16 +1,15 @@
 import os
 
 config = {
     #########################################################################
     ######## MACOSX GENERIC CONFIG KEYS/VAlUES
 
     'default_actions': [
-        'clobber',
         'build',
     ],
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'vcs_share_base': '/builds/hg-shared',
     # allows triggering of dependent jobs when --artifact try syntax is detected
     'perfherder_extra_options': ['artifact'],
     #########################################################################

--- a/testing/mozharness/configs/builds/releng_sub_mac_configs/64_cross_debug.py
+++ b/testing/mozharness/configs/builds/releng_sub_mac_configs/64_cross_debug.py
@@ -1,13 +1,12 @@
 import os
 
 config = {
     'default_actions': [
-        'clobber',
         'build',
         'update',  # decided by query_is_nightly()
     ],
     'stage_platform': 'macosx64-debug',
     'debug_build': True,
     #### 64 bit build specific #####
     'env': {
         'MOZBUILD_STATE_PATH': os.path.join(os.getcwd(), '.mozbuild'),

--- a/testing/mozharness/configs/builds/releng_sub_mac_configs/64_cross_fuzzing_asan.py
+++ b/testing/mozharness/configs/builds/releng_sub_mac_configs/64_cross_fuzzing_asan.py
@@ -1,13 +1,12 @@
 import os
 
 config = {
     'default_actions': [
-        'clobber',
         'build',
     ],
     'stage_platform': 'macosx64-fuzzing-asan',
     'publish_nightly_en_US_routes': False,
     'platform_supports_post_upload_to_latest': False,
     #### 64 bit build specific #####
     'env': {
         'MOZBUILD_STATE_PATH': os.path.join(os.getcwd(), '.mozbuild'),
@@ -20,9 +19,10 @@ config = {
         'MOZ_CRASHREPORTER_NO_REPORT': '1',
         'LC_ALL': 'C',
         'ASAN_OPTIONS': 'detect_leaks=0',
         ## 64 bit specific
         'PATH': '/usr/local/bin:/bin:\
 /usr/bin:/usr/local/sbin:/usr/sbin:/sbin',
     },
     'mozconfig_variant': 'nightly-fuzzing-asan',
+    'artifact_flag_build_variant_in_try': None,
 }

--- a/testing/mozharness/configs/builds/releng_sub_mac_configs/64_debug_artifact.py
+++ b/testing/mozharness/configs/builds/releng_sub_mac_configs/64_debug_artifact.py
@@ -1,16 +1,15 @@
 import os
 
 config = {
     #########################################################################
     ######## MACOSX GENERIC CONFIG KEYS/VAlUES
 
     'default_actions': [
-        'clobber',
         'build',
     ],
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'vcs_share_base': '/builds/hg-shared',
     # debug specific
     'debug_build': True,
     # allows triggering of test jobs when --artifact try syntax is detected