Anti-loop: forward DRY sampler + forward-only nudges (0.3.4)

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "localcode"
-version = "0.3.3"
+version = "0.3.4"
 description = "High-performance AI coding on consumer hardware."
 readme = "README.md"
 requires-python = ">=3.10"

src/localcode/__init__.py

@@ -1,3 +1,3 @@
 __all__ = ["__version__"]
 
-__version__ = "0.3.3"
+__version__ = "0.3.4"

src/localcode/agent/recovery.py

@@ -365,36 +365,36 @@ def churn_nudge_for(signal: ChurnSignal) -> str:
     Names the concrete subject (file path / command) + count so the model
     sees what it's thrashing on, then tells it the ONE thing to do instead.
     """
+    # NOTE: these are FORWARD-ONLY imperatives. They deliberately contain NO
+    # self-referential loop language ("you're going in circles", "you've
+    # rewritten X N times", "thrashing", "stop planning"). A small model
+    # parrots whatever we inject: injecting "you're going in circles" as a
+    # user-role message makes it reply "You're right, I've been going in
+    # circles" — which then sits in its own context and self-conditions the
+    # loop deeper (arXiv:2509.09677). So we tell it the NEXT concrete action
+    # and nothing about the failure it just had.
     if signal.mode is ChurnMode.FILE_REWRITE:
         return (
-            f"SYSTEM: You've rewritten {signal.subject} {signal.count} times "
-            "this turn. Stop rewriting it. Read the ACTUAL error output from "
-            "the last failure, identify the specific line/cause, and make ONE "
-            "targeted edit_file change to fix that — do not overwrite the whole "
-            "file again."
+            f"SYSTEM: {signal.subject} is written — move on to the next file. "
+            "If it has a specific error, make ONE targeted edit_file change to "
+            "the exact line; otherwise create the next file the task needs."
         )
     if signal.mode is ChurnMode.COMMAND_FAILURE:
         return (
-            f"SYSTEM: `{signal.subject}` has failed {signal.count} times this "
-            "turn. Re-running it will not help. Read its error output line by "
-            "line, fix the ROOT CAUSE (a missing dependency, a syntax error in "
-            "a config/source file, a wrong path), and only then run it again."
+            f"SYSTEM: `{signal.subject}` won't succeed as-is. Read its error "
+            "output, fix the root cause (missing dependency, a syntax error in a "
+            "config/source file, a wrong path) with an edit, then run it once."
         )
     if signal.mode is ChurnMode.PLANNING_SPIN:
         return (
-            "SYSTEM: You've spent several rounds planning and re-deriving the "
-            "same approach without changing a single file or running a build. "
-            "You've planned enough. Take ONE concrete action NOW: create or "
-            "edit the most important file for the next step, then build/run to "
-            "verify it. Do not restate the plan — execute the first step of it."
+            "SYSTEM: Take the next concrete action now — create or edit the next "
+            "file the task needs, then run the build to verify. Write code, not "
+            "a plan."
         )
     # INVESTIGATION_SPIN
     return (
-        "SYSTEM: Several rounds of reading/listing/searching without WRITING "
-        "anything — you're going in circles. STOP exploring. If the task is to "
-        "build something, create the target file and write real code THIS round "
-        "with write_file/edit_file; do NOT read, ls, find, cat, or grep again. "
-        "Leftover files on disk are NOT your progress (may be an unrelated run) — "
-        "only files YOU write count. If you truly lack info only the user has, "
-        "ask ONE focused question; otherwise start writing now."
+        "SYSTEM: Take a concrete action now — create the next file the task "
+        "needs and write real code with write_file/edit_file. Files already on "
+        "disk that you did not create are not part of your task. If you truly "
+        "lack information only the user has, ask ONE focused question."
     )

src/localcode/runtime.py

@@ -168,6 +168,21 @@ def _log_disconnect_context(stage: str, error: Any, *, mid_stream: bool = False)
     diag["stage"] = stage
     diag["mid_stream"] = mid_stream
     diag["error"] = err_str[:500]
+    # Capture the SERVER's own last words. llama-server prints the real cause
+    # (ggml/Metal allocation failure, GGML_ASSERT, OOM) to server.log right
+    # before it dies; without this we only see httpx's "connection dropped"
+    # and are left guessing. The tail is the actual diagnosis.
+    _server_tail = ""
+    try:
+        from .paths import global_state_dir
+        _lp = global_state_dir() / "server.log"
+        if _lp.exists():
+            _lines = _lp.read_text(errors="replace").splitlines()
+            _server_tail = "\n".join(_lines[-15:])[-1500:]
+    except Exception:
+        _server_tail = ""
+    if _server_tail:
+        diag["server_log_tail"] = _server_tail
     try:
         from .server_manager import _lifecycle_log as _ll
         _ll("server_disconnect", **diag)
@@ -186,6 +201,8 @@ def _log_disconnect_context(stage: str, error: Any, *, mid_stream: bool = False)
                 f"pressure_kill={diag.get('pressure_kill')} "
                 f"running={diag.get('running')} mid_stream={mid_stream} "
                 f"free_mb={diag.get('free_mb')} error={err_str[:300]}\n"
+                + (f"  server.log tail:\n    "
+                   + _server_tail.replace("\n", "\n    ") + "\n" if _server_tail else "")
             )
     except Exception:
         pass
@@ -2064,6 +2081,25 @@ def _payload(
             # revert this hunk and accept occasional rephrase as a
             # model property of Qwen3.6 IQ2_M.
             payload["repeat_penalty"] = 1.05
+            # Forward the EOS-NEUTRAL anti-loop samplers that were previously
+            # computed into `opts` and then DROPPED (they only went to the dead
+            # ollama-shaped payload below). DRY penalises repeated N-GRAMS —
+            # not single tokens — so unlike repeat_penalty it does NOT suppress
+            # the EOS/sentence-end tokens that caused the 2026-04-29 paraphrase
+            # regression; min_p trims the low-probability tail that token-
+            # collapse loops feed on. llama-server has DRY OFF by default, so
+            # NOT forwarding these is a real root cause of the repeat-collapse
+            # loops. We deliberately do NOT re-add the aggressive repeat_penalty
+            # /top_k/top_p bundle (that was the regression). A/B back to
+            # temperature-only with LOCALCODE_SAMPLER_MINIMAL=1.
+            import os as _os
+            if _os.environ.get("LOCALCODE_SAMPLER_MINIMAL") != "1":
+                payload["dry_multiplier"] = opts["dry_multiplier"]
+                payload["dry_base"] = opts["dry_base"]
+                payload["dry_allowed_length"] = opts["dry_allowed_length"]
+                payload["dry_penalty_last_n"] = opts["dry_penalty_last_n"]
+                if opts.get("min_p", 0):
+                    payload["min_p"] = opts["min_p"]
             if "num_predict" in opts:
                 _np = opts["num_predict"]
                 # llama-server treats max_tokens=-1 as "use default", which on
@@ -2080,8 +2116,11 @@ def _payload(
             # outbound chat-completions payload so we can verify DRY is
             # actually being forwarded. Set LOCALCODE_DEBUG_SAMPLERS=1
             # to enable. Self-disables after one log to keep noise down.
-            import os, logging
-            if os.environ.get("LOCALCODE_DEBUG_SAMPLERS") == "1" and not getattr(self, "_logged_samplers", False):
+            import logging
+            # Always log the ACTUAL forwarded samplers once per session (was
+            # opt-in) so we can correlate looping with the real server config —
+            # the "control this better" record. Cheap: fires exactly once.
+            if not getattr(self, "_logged_samplers", False):
                 sampler_keys = (
                     "temperature", "top_p", "top_k", "min_p",
                     "repeat_penalty", "repeat_last_n",

src/localcode/server_manager.py

@@ -71,12 +71,9 @@
     lifecycle_log_path,
 )
 
-# PID file stays GLOBAL — only one llama-server runs on the machine
-# (single port, single GPU memory budget). When you `cd` between
-# projects mid-session, the running server stays serving you. The
-# per-project lifecycle log records a fresh `server_started` entry
-# on next launch from the new project. See paths.py for the full
-# global-vs-project split rationale.
+# PID file stays GLOBAL — only one llama-server runs per machine (single port,
+# single GPU budget), so it keeps serving you when you `cd` between projects.
+# See paths.py for the global-vs-project split rationale.
 PID_FILE = server_pid_file()
 DEFAULT_PORT = 8081
 # Preferred-range scan (8081-8099) before falling through to an OS-assigned
@@ -177,13 +174,9 @@ def _rewrite_port_arg(cmd: list[str], port: int) -> list[str]:
 
 STUCK_SERVER_MARKER = stuck_server_marker_path()
 
-# Persistent (append-only) lifecycle log for every server start, stop,
-# pressure-kill, and recovery event. Distinct from the per-session
-# `~/.local/share/localcode/server.log` (which the setup screen
-# overwrites with `open(..., "w")` on every launch and so loses
-# inter-session context). Per-project (lives at
-# `<project_root>/.localcode/lifecycle.log`) so each project has its
-# own diagnostic timeline.
+# Persistent (append-only) lifecycle log for every server start/stop/kill/
+# recovery event. Per-project (`<project_root>/.localcode/lifecycle.log`) so
+# each project keeps its own diagnostic timeline across sessions.
 LIFECYCLE_LOG = lifecycle_log_path()
 
 
@@ -400,12 +393,11 @@ def start(self, cmd: list[str], model_path: str, port: int = DEFAULT_PORT,
             had_prior = self._process is not None
             _prev_model = self._model_path  # capture before shutdown clears it
             self._shutdown_locked()
-            # Wait for the OLD server's memory to actually release before
-            # spawning the new one: the kernel may take 1-3 s to free wired
-            # Metal memory after the child reaps, and spawning the new ~10 GB
-            # server in that window double-commits and trips the pressure
-            # monitor on a 16 GB Mac. Best-effort — targets ~11 GB free, times
-            # out at 8 s, and proceeds anyway (refusing would be worse).
+            # Wait for the OLD server's memory to release before spawning the
+            # new one: the kernel takes 1-3 s to free wired Metal memory after
+            # the child reaps, and spawning into that window double-commits and
+            # trips the pressure monitor on a 16 GB Mac. Best-effort — targets
+            # ~11 GB free, times out at 8 s, proceeds anyway.
             if had_prior:
                 # Only a genuine model change is "model_switch"; a same-model
                 # relaunch (crash/disconnect recovery) is "server_restart".
@@ -430,20 +422,35 @@ def start(self, cmd: list[str], model_path: str, port: int = DEFAULT_PORT,
             # AGX driver may read the env at first Metal touch — setting it in
             # the parent env before spawn is the belt-and-suspenders approach.
             env.setdefault("AGX_RELAX_CDM_CTXSTORE_TIMEOUT", "1")
+            # Capture the server's OWN stdout/stderr to server.log (this runtime
+            # path used to send both to /dev/null, discarding llama-server's
+            # final ggml/Metal error on the recurring -9). Append per-spawn.
+            log_fh = None
+            try:
+                from .paths import global_state_dir
+                log_fh = open(global_state_dir() / "server.log", "a", buffering=1)
+                log_fh.write(f"\n===== llama-server spawn (port {port}) =====\n")
+            except Exception:
+                log_fh = None
+            try:  # close any prior spawn's handle before replacing it
+                if getattr(self, "_log_fh", None) is not None:
+                    self._log_fh.close()
+            except Exception:
+                pass
+            self._log_fh = log_fh
             self._process = subprocess.Popen(
                 cmd,
-                stdout=subprocess.DEVNULL,
-                stderr=subprocess.DEVNULL,
+                stdout=(log_fh or subprocess.DEVNULL),
+                stderr=subprocess.STDOUT if log_fh else subprocess.DEVNULL,
                 start_new_session=True,  # process group leader → killpg works
                 env=env,
             )
             self._model_path = model_path
             self._port = port
 
-            # Layer 1: kernel-enforced memory ceiling via jetsam. If
-            # llama-server tries to wire more than the budget allows,
-            # macOS kernel kills it BEFORE the vm_fault wait-chain can
-            # form. This is the hard backstop — sanctioned Apple API.
+            # Layer 1: kernel-enforced memory ceiling via jetsam — the hard
+            # backstop (sanctioned Apple API) that kills llama-server before it
+            # can push the system over the edge.
             try:
                 from .memory_guard import (
                     set_jetsam_highwater, recommended_jetsam_limit_mb,
@@ -467,14 +474,10 @@ def start(self, cmd: list[str], model_path: str, port: int = DEFAULT_PORT,
             except Exception:
                 self._pressure_thread = None
             self._write_pid_file(self._process.pid)
-            # Log the FULL command we launched with so future debugging
-            # can answer "what flags was the server using during this
-            # session?" — needed because subtle flags like
-            # `--lookup-cache-dynamic` or `--spec-type ngram-mod` cause
-            # repetition pathologies that look like model bugs but are
-            # actually decode-time speculative-cache feedback loops.
-            # Truncated to 4000 chars to keep the event small; that's
-            # enough for ~80 args.
+            # Log the FULL launch command so debugging can answer "what flags
+            # was the server using?" — subtle flags (e.g. --spec-type ngram-mod)
+            # cause repetition pathologies that look like model bugs. Truncated
+            # to 4000 chars (~80 args) to keep the event small.
             _flags_str = " ".join(str(c) for c in cmd)[:4000]
             _lifecycle_log("server_started", pid=self._process.pid, port=port,
                            model=Path(model_path).name,

tests/test_churn_detection.py

@@ -80,8 +80,10 @@ def test_investigation_spin_outranks_planning_spin():
 def test_planning_spin_nudge_is_actionable():
     sig = detect_churn({}, {}, 0, planning_streak=CHURN_PLANNING_STREAK_LIMIT)
     text = churn_nudge_for(sig)
-    assert "planned enough" in text.lower()
-    assert "concrete action" in text.lower() or "execute" in text.lower()
+    # Forward-only imperative: tells it the next action, with NO echo-able
+    # self-critical loop language ("planned enough") a small model would parrot.
+    assert "concrete action" in text.lower() or "write code" in text.lower()
+    assert "planned enough" not in text.lower() and "circles" not in text.lower()
 
 
 def test_command_failure_takes_precedence_over_file_rewrite():