Timeout misclassification and fallback loop fixes

Fixes on record

Merged to main. A stamp counts the issues a fix is linked to.

• #22780 fix(fallback): skip chain entries matching current provider/model/base_url

  merged to main

  files: run_agent.py, tests/run_agent/test_provider_fallback.py

  Show the diff

  • run_agent.py

    @@ -8042,6 +8042,32 @@ def _try_activate_fallback(self, reason: "FailoverReason | None" = None) -> bool
             if not fb_provider or not fb_model:
                 return self._try_activate_fallback()  # skip invalid, try next
     
    +        # Skip entries that resolve to the current (provider, model) — falling
    +        # back to the same backend that just failed loops the failure. Compare
    +        # base_url too so two distinct custom_providers entries pointing at the
    +        # same shim/proxy URL also dedup. See issue #22548.
    +        current_provider = (getattr(self, "provider", "") or "").strip().lower()
    +        current_model = (getattr(self, "model", "") or "").strip()
    +        current_base_url = str(getattr(self, "base_url", "") or "").rstrip("/").lower()
    +        fb_base_url_for_dedup = (fb.get("base_url") or "").strip().rstrip("/").lower()
    +        if fb_provider == current_provider and fb_model == current_model:
    +            logging.warning(
    +                "Fallback skip: chain entry %s/%s matches current provider/model",
    +                fb_provider, fb_model,
    +            )
    +            return self._try_activate_fallback()
    +        if (
    +            fb_base_url_for_dedup
    +            and current_base_url
    +            and fb_base_url_for_dedup == current_base_url
    +            and fb_model == current_model
    +        ):
    +            logging.warning(
    +                "Fallback skip: chain entry base_url %s matches current backend",
    +                fb_base_url_for_dedup,
    +            )
    +            return self._try_activate_fallback()
    +
             # Use centralized router for client construction.
             # raw_codex=True because the main agent needs direct responses.stream()
             # access for Codex providers.

  • tests/run_agent/test_provider_fallback.py

    @@ -220,3 +220,88 @@ def test_multiple_credentials_all_in_cooldown_returns_false(self):
     
         def test_many_credentials_available_returns_true(self):
             assert _pool_may_recover_from_rate_limit(_pool(10)) is True
    +
    +
    +# ── Skip-self dedup (#22548) ───────────────────────────────────────────────
    +
    +
    +class TestFallbackChainDedup:
    +    """A fallback chain entry that resolves to the current provider/model
    +    (or the same custom-provider base_url) must be skipped, not retried.
    +    Otherwise a misconfigured chain or two custom_providers entries pointing
    +    at the same shim loop the same failure. See issue #22548."""
    +
    +    def test_skips_entry_matching_current_provider_and_model(self):
    +        """Chain has [same-as-current, real-fallback]; activate must skip
    +        the first and use the second."""
    +        fbs = [
    +            # First entry == current state. Should be skipped.
    +            {"provider": "openrouter", "model": "z-ai/glm-4.7"},
    +            # Second entry: real fallback.
    +            {"provider": "zai", "model": "glm-4.7"},
    +        ]
    +        agent = _make_agent(fallback_model=fbs)
    +        agent.provider = "openrouter"
    +        agent.model = "z-ai/glm-4.7"
    +        agent.base_url = "https://openrouter.ai/api/v1"
    +
    +        # Stub out resolve_provider_client so we can assert which entry was
    +        # actually used — return a MagicMock client tagged with the provider.
    +        called = []
    +        def _resolve(provider, model=None, raw_codex=False, **kwargs):
    +            called.append((provider, model))
    +            return _mock_client(), model
    +        with patch("agent.auxiliary_client.resolve_provider_client", side_effect=_resolve):
    +            with patch("hermes_cli.model_normalize.normalize_model_for_provider", side_effect=lambda m, p: m):
    +                ok = agent._try_activate_fallback()
    +
    +        assert ok is True
    +        # The first entry was skipped — only the second reached resolve.
    +        assert called == [("zai", "glm-4.7")], (
    +            f"expected fallback to skip same-state entry, got call order: {called}"
    +        )
    +
    +    def test_skips_entry_matching_current_base_url_and_model(self):
    +        """Two custom_providers entries pointing at the same shim URL
    +        with the same model should dedup even if their provider names differ."""
    +        fbs = [
    +            # Different provider name but same shim URL + model — same backend.
    +            {"provider": "claude-cli-alt", "model": "claude-opus-4.7",
    +             "base_url": "http://127.0.0.1:7891/v1"},
    +            # Real different fallback.
    +            {"provider": "openrouter", "model": "anthropic/claude-opus-4.7"},
    +        ]
    +        agent = _make_agent(fallback_model=fbs)
    +        agent.provider = "claude-cli"
    +        agent.model = "claude-opus-4.7"
    +        agent.base_url = "http://127.0.0.1:7891/v1"
    +
    +        called = []
    +        def _resolve(provider, model=None, raw_codex=False, **kwargs):
    +            called.append((provider, model))
    +            return _mock_client(), model
    +        with patch("agent.auxiliary_client.resolve_provider_client", side_effect=_resolve):
    +            with patch("hermes_cli.model_normalize.normalize_model_for_provider", side_effect=lambda m, p: m):
    +                ok = agent._try_activate_fallback()
    +
    +        assert ok is True
    +        # Same shim/base_url+model entry skipped, second one used.
    +        assert called == [("openrouter", "anthropic/claude-opus-4.7")], (
    +            f"expected base_url-aware dedup, got call order: {called}"
    +        )
    +
    +    def test_returns_false_when_only_self_matching_entries(self):
    +        """A chain with only self-matching entries exhausts to False."""
    +        fbs = [
    +            {"provider": "openrouter", "model": "z-ai/glm-4.7"},
    +        ]
    +        agent = _make_agent(fallback_model=fbs)
    +        agent.provider = "openrouter"
    +        agent.model = "z-ai/glm-4.7"
    +        agent.base_url = "https://openrouter.ai/api/v1"
    +
    +        with patch("agent.auxiliary_client.resolve_provider_client") as mock_resolve:
    +            ok = agent._try_activate_fallback()
    +
    +        assert ok is False
    +        mock_resolve.assert_not_called()

• #22857 fix(error_classifier): classify generic-typed timeout messages as transient (carve-out of #22664)

  merged to main

  files: agent/error_classifier.py, tests/agent/test_error_classifier.py