--- a/testing/mozharness/configs/builds/taskcluster_firefox_win32_clang.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_win32_clang.py
@@ -16,24 +16,16 @@ config = {
     # - taskcluster_firefox_win64_clang
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_win32_clang_debug.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_win32_clang_debug.py
@@ -16,24 +16,16 @@ config = {
     # - taskcluster_firefox_win64_clang
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_win32_noopt_debug.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_win32_noopt_debug.py
@@ -18,24 +18,16 @@ config = {
     # - taskcluster_firefox_win32_noopt_debug
     # - taskcluster_firefox_win64_noopt_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_win32_rusttests_opt.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_win32_rusttests_opt.py
@@ -16,24 +16,16 @@ config = {
     # - taskcluster_firefox_win64_clang
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_win64_asan_debug.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_win64_asan_debug.py
@@ -16,24 +16,16 @@ config = {
     # - taskcluster_firefox_win64_clang
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_win64_asan_opt.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_win64_asan_opt.py
@@ -16,24 +16,16 @@ config = {
     # - taskcluster_firefox_win64_clang
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_win64_clang.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_win64_clang.py
@@ -16,24 +16,16 @@ config = {
     # - taskcluster_firefox_win64_clang
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_win64_clang_debug.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_win64_clang_debug.py
@@ -16,24 +16,16 @@ config = {
     # - taskcluster_firefox_win64_clang
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_win64_noopt_debug.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_win64_noopt_debug.py
@@ -16,24 +16,16 @@ config = {
     # - taskcluster_firefox_win64_clang
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_win64_rusttests_opt.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_win64_rusttests_opt.py
@@ -16,24 +16,16 @@ config = {
     # - taskcluster_firefox_win64_clang
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_windows_32_addondevel.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_windows_32_addondevel.py
@@ -16,24 +16,16 @@ config = {
     # - taskcluster_firefox_win64_clang
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': False,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_windows_32_debug.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_windows_32_debug.py
@@ -16,24 +16,16 @@ config = {
     # - taskcluster_firefox_win64_clang
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_windows_32_opt.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_windows_32_opt.py
@@ -17,24 +17,16 @@ config = {
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
         'update',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_windows_64_addondevel.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_windows_64_addondevel.py
@@ -17,24 +17,16 @@ config = {
     # - taskcluster_firefox_win64_clang_debug
     # - taskcluster_firefox_win64_addonsdevel
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': False,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_windows_64_debug.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_windows_64_debug.py
@@ -16,24 +16,16 @@ config = {
     # - taskcluster_firefox_win64_clang
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],

--- a/testing/mozharness/configs/builds/taskcluster_firefox_windows_64_opt.py
+++ b/testing/mozharness/configs/builds/taskcluster_firefox_windows_64_opt.py
@@ -17,24 +17,16 @@ config = {
     # - taskcluster_firefox_win64_clang_debug
 
     'default_actions': [
         'clone-tools',
         'build',
         'check-test',
         'update',
     ],
-    'exes': {
-        'virtualenv': [
-            sys.executable,
-            os.path.join(
-                os.getcwd(), 'build', 'src', 'third_party', 'python', 'virtualenv', 'virtualenv.py'
-            )
-        ],
-    },
     'app_ini_path': '%(obj_dir)s/dist/bin/application.ini',
     # decides whether we want to use moz_sign_cmd in env
     'enable_signing': True,
     'vcs_share_base': os.path.join('y:', os.sep, 'hg-shared'),
     'tooltool_script': [
       sys.executable,
       os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')
     ],