From 7172f0d775fa07e0be7760ca08a6a519639910c7 Mon Sep 17 00:00:00 2001
From: giles <giles.bradshaw@rose-ash.com>
Date: Sun, 28 Jun 2026 19:13:54 +0000
Subject: [PATCH] =?UTF-8?q?host:=20100%=20serving=20JIT=20=E2=80=94=20drop?=
 =?UTF-8?q?=20the=20host=20jit-exclude=20(surface=20miscompiles=20in=20dev?=
 =?UTF-8?q?)?=
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Per dev intent: don't mask JIT errors. Remove (jit-exclude! "host/*" "dream-*"
"dr/*") so ALL request-path SX runs under JIT. Host handlers miscompile on first
call in the http-listen path (map/rest arg bug → 500, self-heals on retry); that
surfacing is the point — it exercises the JIT against real durable-IO traffic and
gives the sx-vm-extensions loop the full miscompile list to fix (kernel bugs A/B
in plans/HANDOFF-jit-miscompile.md). Datalog JIT win stays (/tags fast).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 lib/host/serve.sh | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/lib/host/serve.sh b/lib/host/serve.sh
index 3a972938..55bf96ab 100755
--- a/lib/host/serve.sh
+++ b/lib/host/serve.sh
@@ -99,17 +99,13 @@ EPOCH=1
   for M in "${MODULES[@]}"; do
     echo "(epoch $EPOCH)"; echo "(load \"$M\")"; EPOCH=$((EPOCH+1))
   done
-  # Serving-mode JIT: exclude the request-path SX (host app + Dream framework) from
-  # JIT. Those functions miscompile on first call in the http-listen + cek_run_with_io
-  # path (a map/rest arg bug → 500, then self-heals via CEK fallback — but the first
-  # hit fails). They're IO-bound anyway, so CEK is no slower. The JIT win is the
-  # Datalog/relations saturation (dl-*/relations-*), which JITs cleanly and stays on
-  # (e.g. /tags 2.5s -> 0.76s).
-  if [ "${SX_SERVING_JIT:-}" = "1" ]; then
-    echo "(epoch $EPOCH)"
-    echo "(eval \"(jit-exclude! \\\"host/*\\\" \\\"dream-*\\\" \\\"dr/*\\\")\")"
-    EPOCH=$((EPOCH+1))
-  fi
+  # Serving-mode JIT runs at 100% — NO host jit-exclude. The request-path SX (host
+  # app + Dream framework) miscompiles on first call in the http-listen +
+  # cek_run_with_io path (map/rest arg bug → 500, self-heals on retry via CEK
+  # fallback). That's deliberate in DEV: surfacing every miscompile (the
+  # `[jit] … first-call fallback` log lines) exercises the JIT against real traffic
+  # and feeds the bug list to the sx-vm-extensions loop. Do NOT mask it with a
+  # jit-exclude — see plans/HANDOFF-jit-miscompile.md.
   # Point the blog at the DURABLE file backend (persists under $SX_PERSIST_DIR),
   # then idempotently seed a welcome post (sx_content = SX element markup, the
   # editor's content model). Re-seeding is a no-op if the slug already exists.