Bug 1903631 - Disable the socket process in mach xpcshell r=nalexander

Differential Revision: https://phabricator.services.mozilla.com/D214298

js/xpconnect/mach_commands.py

@@ -30,6 +30,11 @@ def xpcshell(command_context, args):
         str(browser_dir),
     ]
 
+    # Disable the socket process (see https://bugzilla.mozilla.org/show_bug.cgi?id=1903631).
+    env = {
+        "MOZ_DISABLE_SOCKET_PROCESS": "1",
+    }
+
     if args:
         command.extend(args)
 
@@ -37,4 +42,5 @@ def xpcshell(command_context, args):
         command,
         pass_thru=True,
         ensure_exit_code=False,
+        append_env=env,
     )