`hermes -t web chat` silently dropped the toolset filter (and the same
hold true for `-m`, `--provider`, `--tui`, `--dev` placed before
`chat`). Reported in #28780 for `-t/--toolsets`; the others are sibling
failures with the same root cause.
Root cause: the chat subparser re-declared these flags with `default=None`
(or `default=False` for store_true) on top of the matching top-level
parser flags. When argparse dispatches into the subparser it shares the
namespace via `dest`, so the subparser's default overwrites whatever the
top-level parser parsed before the subcommand. `-s/--skills`, `-r/-c/-w`,
`--yolo`, and `--pass-session-id` already use `default=argparse.SUPPRESS`
for exactly this reason — the chat-subparser action becomes a no-op
unless the user explicitly passes the flag after `chat`, and the parent
value survives.
Reproduction (origin/main, before fix):
>>> parser.parse_known_args(["-t", "web", "chat"]).toolsets
None
>>> parser.parse_known_args(["chat", "-t", "web"]).toolsets
'web'
After fix:
>>> parser.parse_known_args(["-t", "web", "chat"]).toolsets
'web'
>>> parser.parse_known_args(["chat", "-t", "web"]).toolsets
'web'
Sibling flags fixed in the same commit because they share the exact same
argparse pattern bug — verified via a new contract test that scans every
chat-subparser action whose `dest` is also on the top-level parser and
asserts `default is argparse.SUPPRESS`. The test fails on origin/main
listing all five offenders and passes after this fix.
Test additions in tests/hermes_cli/test_argparse_flag_propagation.py:
- TestChatSubparserInheritedValueFlags exercising real `_parser` build
(not the hand-rolled replica) so it catches future drift.
- Parametrized before-chat / after-chat cases for `-t`, `--toolsets`,
`-m`, `--model`, `--provider`.
- Negative case: passing none of the flags leaves attrs at the top-level
parser's `None` default (SUPPRESS does not remove existing attrs).
- Combined case: all three value flags before `chat` simultaneously.
- store_true cases for `--tui` / `--dev`.
- Contract test asserting every shared-`dest` flag on chat uses SUPPRESS.
Fixes#28780.
briandevans
5ecc07986f