1 files changed, 11 insertions, 4 deletions

diff --git a/src/mailman/bin/master.py b/src/mailman/bin/master.py
index 6dc2a451f..e7efdc537 100644
--- a/src/mailman/bin/master.py
+++ b/src/mailman/bin/master.py
@@ -353,7 +353,7 @@ class Loop:
         # Set the environment variable which tells the runner that it's
         # running under bin/master control.  This subtly changes the error
         # behavior of bin/runner.
-        os.environ['MAILMAN_UNDER_MASTER_CONTROL'] = '1'
+        env = {'MAILMAN_UNDER_MASTER_CONTROL': '1'}
         # Craft the command line arguments for the exec() call.
         rswitch = '--runner=' + spec
         # Wherever master lives, so too must live the runner script.
@@ -361,14 +361,21 @@ class Loop:
         # config.PYTHON, which is the absolute path to the Python interpreter,
         # must be given as argv[0] due to Python's library search algorithm.
         args = [sys.executable, sys.executable, exe, rswitch]
-        if self._config_file is not None:
-            args.extend(['-C', self._config_file])
+        # Always pass the explicit path to the configuration file to the
+        # sub-runners.  This avoids any debate about which cfg file is used.
+        config_file = (config.filename if self._config_file is None
+                       else self._config_file)
+        args.extend(['-C', config_file])
         log = logging.getLogger('mailman.runner')
         log.debug('starting: %s', args)
+        # We must pass this environment variable through if it's set,
+        # otherwise runner processes will not have the correct VAR_DIR.
+        var_dir = os.environ.get('MAILMAN_VAR_DIR')
+        if var_dir is not None:
+            env['MAILMAN_VAR_DIR'] = var_dir
         # For the testing framework, if this environment variable is set, pass
         # it on to the subprocess.
         coverage_env = os.environ.get('COVERAGE_PROCESS_START')
-        env = dict()
         if coverage_env is not None:
             env['COVERAGE_PROCESS_START'] = coverage_env
         args.append(env)