`MoAPresetNotFoundError` subclasses ValueError, so `is_local_validation_error`
re-opened the fallback the classifier had just refused (#55933). Only an
UNCLASSIFIED (reason=unknown) local error keeps the historical fallback.
Test exercises the real exception through settlement, not the classifier bool.
Two CI regressions from the previous commit, both mine:
- `_moa_special_cases` was switched to `_ABORT_FALLBACK`, which flips
`should_fallback` to True for the MoA adapter-shape and missing-preset
verdicts. #55933 made those deliberately NOT fall back (a fallback would
silently replace the MoA route with a single model); restore
`retryable=False` only. The gate in `settle_unrecovered_error` now honours
that for real: on main these verdicts never reached the fallback branch
because the flag was never consulted.
- `tests/agent/test_prompt_cache_ttl_propagation.py` pins every
`_try_activate_fallback` reference to a direct `if agent._try_activate_fallback():`
site (#84733 restart discipline); `fallback_allowed and agent._try_activate_fallback()`
broke that shape. Nest the two calls under one `if should_fallback or local_validation:`
block instead.
When a proxy (Ollama, OpenRouter) rejects the MODEL's own unparseable
tool-call JSON with `400 invalid tool call arguments`, the classifier returned
the generic format_error verdict (`should_fallback=True`) and the non-retryable
client-error path cascaded through every fallback provider: 4-5 sequential
calls, 20-60s per occurrence, ending on a model that produced the same broken
JSON (#12770).
- error_classifier: explicit `_MALFORMED_TOOL_ARGS_PATTERNS` checked before the
request-validation and overflow heuristics, returning format_error with
`retryable=False, should_fallback=False`.
- turn_api_error: the client-error settlement honours `should_fallback`; the
verdicts that legitimately reach that branch (policy block, TLS chain, MoA
shape/preset errors) now state `should_fallback=True` explicitly, so the gate
changes behaviour only for the new verdict. Local validation errors keep
their historical fallback.
Fixes#12770. Pattern list and gating approach from #16022 by @cuyua9 (stale
base); tests trimmed to two invariants.
Co-authored-by: cuyua9 <2114364329@qq.com>
The two facades post-#102117 (chat_completion_helpers, agent_runtime_helpers) must not grow
behaviour; the marker/predicate belong with the sibling that already owns primary-cooldown
state shared by the fallback walk and restore_primary_runtime. Also drops the two
try/except-return-False wrappers around pool.entries() and normalize_model_for_provider
(neither raises for a live pool / the never-raising normalizer).
Tests trimmed to the two invariants (#106475): the marker fires only on the single-credential
Codex entitlement 400 and the walk skips the rejected slug in either form; restore is gated on
a rejected primary and still restores an unrelated one.
A Codex ChatGPT-account 400 ('The X model is not supported when using Codex
with a ChatGPT account.') names the model, so with a single credential the
slug is dead for that account. The fallback walk still re-selected it and
restore_primary_runtime switched back to the primary at the start of every
turn, announcing an unverified 'Primary model restored' — the two warnings
alternated forever with zero delivered answers (#106475).
Record the rejected (provider, model) pair on the non-retryable client-error
path (only when no multi-credential pool exists — rotation covers that case,
#71970), skip rejected entries during the fallback walk, and gate
restore_primary_runtime on the primary's slug so the session fails closed
with the terminal entitlement error instead of oscillating. Fixes#106475.
(cherry picked from commit 471435b10288f15387b2549a8b02551d82c0f670)
