Follow-up to the salvaged #101894 (@jwilson411). The over-threshold
"reclamation did not run" warning is deduped on (reason, rearm mark), and
the key was only cleared when a prune committed. Every other path that
zeroes the rearm mark — compress(), on_session_reset/on_session_end,
bind_session_state, update_model — left the key in place, so a lockout
that warned at rearm=0, then a full compaction, then the same lockout
again was silent, contradicting the helper's own "warns again" contract
(and leaking the key across sessions on a rebound compressor).
- ContextCompressor._reset_proactive_prune_rearm(): one helper for the
five rearm-to-zero sites; clears the dedup key alongside the mark.
- _warn_reclamation_no_op(): dropping back under threshold releases the
key (mirrors _clear_context_overflow_warn semantics on the agent side).
- test_proactive_prune_loop_wiring: the attempts_exhausted fixture now
models the only state the real engine can produce for that branch
(should_compress() is should_compress_info()[0]) — budget spent
(max_compression_attempts=0) with the engine saying RUN, instead of
should_compress=False paired with (True, None).
- Two guards: lockout warns again after a rearm reset; dropping under
threshold releases the key. Both fail with the clears removed.
Message-only rearm could sit just above the body estimate while provider
prompt_tokens (system + tool schemas) already exceeded threshold_tokens,
so prune no-oped forever with no log. Bypass that rearm short-circuit on
the billed basis, warn once when over-threshold reclamation no-ops, and
name attempts_exhausted when should_compress_info says run but the loop
skips.
Fixes#101889
Follow-ups on top of the cherry-picked #62644 mechanism, porting it to
current main and closing the salvage-review requirements:
- proactive_prune_min_reclaim_tokens (default 4096): a prune only COMMITS
when it reclaims a meaningful token batch, measured on the pruned output.
A committed prune rewrites already-sent history and invalidates the
provider prompt-cache prefix; this hysteresis gate keeps those breaks
episodic/amortized (like a compression boundary) instead of firing every
tool iteration. 0 disables the gate. (Design point credited to the
#62389 review cycle's prune_minimum_tokens.)
- Standard no-op caller contract: every skip path returns the INPUT list
object; the loop commits only on 'result is not messages' + non-zero count.
- Loop call is getattr+callable guarded (plugin engines predating the hook,
SimpleNamespace test doubles) and exception-swallowed at debug level.
- Config parse follows the compression.max_attempts hardened semantics:
booleans rejected, fractional floats rejected, integral floats/numeric
strings accepted; negative trigger = disabled.
- cli-config.yaml.example documented (all three keys) and gateway
_CACHE_BUSTING_CONFIG_KEYS extended so hot-reload rebuilds the agent.
- Tests: min-reclaim gate both directions, input-object no-op contract,
no-orphan tool_call_id pairing in BOTH directions (#69830 pin rule),
default-off zero-behavior-change pin, config parse seam, and behavioral
loop-wiring tests (consulted/commit/no-op/absent-method/raising).