Fixed #30584 -- Fixed management command when using subparsers with dest parameter.

tests/user_commands/management/commands/subparser_dest.py

@@ -0,0 +1,13 @@
+from django.core.management.base import BaseCommand
+from django.utils.version import PY37
+
+
+class Command(BaseCommand):
+    def add_arguments(self, parser):
+        kwargs = {'required': True} if PY37 else {}
+        subparsers = parser.add_subparsers(dest='subcommand', **kwargs)
+        parser_foo = subparsers.add_parser('foo')
+        parser_foo.add_argument('--bar')
+
+    def handle(self, *args, **options):
+        self.stdout.write(','.join(options))