MendixMau · Oct 17, 2026 · Oct 16, 2026 · Oct 16, 2026 · Oct 17, 2026 · Oct 17, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -19,6 +19,7 @@ Sections dated before 2026-09-19 predate the cycle and stay as they are. Named m
 
 ## Unreleased
 
+- fix(exec): **the gate keeps mxbuild's full output in a per-run log and names it on screen and in the BUILD-LOG row.** exec.sh printed `head -20` of the output and deleted the rest, so the evidence of a failed gate (a CE1613 detail among it) was lost in a field migration project (12 modules). A gate that does not pass now writes `.mpr-snapshots/.mxbuild-logs/<run>.log` (newest 30 kept; a dot dir, so `restore-mpr.sh` and the snapshot pruning skip it; a clean or delta-gate pass writes none, and a retry always keeps the first attempt's output next to the second); the screen shows the top lines plus the path and the row ends with `mxbuild log: <path>`. Test: `tests/wave2/test-exec-gate-log.sh` (Refs #442, #448, #171, #285, #424) — field migration project
 - fix(exec): **the gate pauses this project's `mxcli run --local --watch` while mxbuild runs and retries once on an infra exit.** The gate's mxbuild and a live watcher both write `deployment/`; in a field migration project (12 modules) 17 of 27 failed gates were "gate could not run" (mxbuild exit 1, no CE code), against 0 of 22 in watcher-free copies. The watcher is stopped (SIGSTOP) for the gate and resumed (SIGCONT, also in the EXIT trap); an exit 1 or 3 with no CE code and no errors file is retried once and the BUILD-LOG row says `retry after infra exit`; a final failure still takes the #424 rollback. The match is exact (the watcher's project dir must equal this project's root, so a sibling `-copy` or a nested worktree watcher is never paused), and the paused pids are recorded in `.mpr-snapshots/.watcher-paused` so the next exec.sh resumes a watcher left stopped by a SIGKILLed one and says so. Test: `tests/wave2/test-exec-gate-retry.sh` (Refs #441, #444, #171, #285, #424) — field migration project
 - learn(load-test): **trap 9, an unlicensed local runtime caps concurrent sessions at 6 ("Maximum number of sessions exceeded!") and stops itself after a random 2 to 4 hours, both reading as the app failing under load; more than 6 users needs a licensed runtime or a cloud sandbox.** Text only, ondemand skill. Source: a personal licence-budget gate written after parallel journey runs hit both — MendixMau
 - fix(progress-report): **the full plan tables (one table per phase plus views A and B) now sit in one closed `<details>` card below the phase cards, so a large plan no longer pushes the rest of the report off screen; the phase cards above stay the summary, and nothing is written when the project has no plan fragment.** Test: P6 in `test-progress-report-polish.sh` — MendixMau

diff --git a/project-bin/_common.sh b/project-bin/_common.sh
@@ -590,6 +590,8 @@ find_java_exe() {
 MXTK_PAUSED_PIDS=""
 MXTK_PAUSED_FILE=""
 MXTK_GATE_RETRY_NOTE=""
+MXTK_GATE_FIRST_OUT=""
+MXTK_GATE_FIRST_EXIT=""
 
 # mxtk_watcher_pids <project-root> - pids of `mxcli run --local --watch` that belong to this
 # project. Exact match only: the watcher's project dir (the directory of its -p argument,
@@ -680,18 +682,21 @@ mxtk_resume_leftover() {
 # on the model; a real model error always names a CE code. An errors file with content (for
 # example a version mismatch in errors[]) is deterministic and is not retried.
 # Prints nothing on stdout (callers discard the count); sets the same MXTK_MXBUILD_* globals as
-# mxtk_mxbuild_error_count, plus MXTK_GATE_RETRY_NOTE ("retry after infra exit" or empty).
+# mxtk_mxbuild_error_count, plus MXTK_GATE_RETRY_NOTE ("retry after infra exit" or empty); after a
+# retry MXTK_GATE_FIRST_OUT / MXTK_GATE_FIRST_EXIT hold the FIRST attempt's output and exit code
+# (the MXTK_MXBUILD_* globals describe the final attempt only).
 # Returns mxtk_mxbuild_error_count's code for the final attempt.
 mxtk_gate_mxbuild() {
   local _mpr="$1" _timeout="${2:-0}" _ef="$3" _rc=0
-  MXTK_GATE_RETRY_NOTE=""
+  MXTK_GATE_RETRY_NOTE=""; MXTK_GATE_FIRST_OUT=""; MXTK_GATE_FIRST_EXIT=""
   mxtk_pause_watchers "${PROJECT_ROOT:-$(dirname "$_mpr")}"
   mxtk_mxbuild_error_count "$_mpr" "$_timeout" "$_ef" >/dev/null || _rc=$?
   case "${MXTK_MXBUILD_EXIT:-}" in
     1|3)
       if [ ! -s "$_ef" ] && ! grep -Eq -- 'CE[0-9]{4}' <<<"${MXTK_MXBUILD_OUT:-}"; then
         echo "  ⚠ retry after infra exit: mxbuild exited $MXTK_MXBUILD_EXIT with no CE code and no errors file; building once more" >&2
         MXTK_GATE_RETRY_NOTE="retry after infra exit"
+        MXTK_GATE_FIRST_OUT="${MXTK_MXBUILD_OUT:-}"; MXTK_GATE_FIRST_EXIT="$MXTK_MXBUILD_EXIT"
         : > "$_ef"
         _rc=0
         mxtk_mxbuild_error_count "$_mpr" "$_timeout" "$_ef" >/dev/null || _rc=$?

diff --git a/project-bin/exec.sh b/project-bin/exec.sh
@@ -437,6 +437,7 @@ BUILD_LOG="$PROJECT_ROOT/docs/BUILD-LOG.md"
 GATE_STATE="not-run"   # not-run | skipped | unverified | pass | fail
 GATE_ERRORS="?"        # mxbuild error count behind a pass (0 = clean); recorded in the stamp
 MXB_WHY=""             # mxbuild's errors[] reason when it exited without checking the model
+MXB_LOG_NOTE=""        # "mxbuild log: <path>" when the gate's full output was saved (BUILD-LOG detail)
 GATE_NOTE=""           # "retry after infra exit" when a gate mxbuild was run twice
 
 # ── Exec approval (auto records itself) ──────────────────────────────────────
@@ -491,7 +492,7 @@ HDR2
   # The gate cell is read from GATE_STATE rather than passed in, so no caller
   # can omit it — a blank cell in this table reads as "fine", which is the exact
   # false-green the gate exists to prevent.
-  _detail="$2${CHANGE_CLASS:+ · change: $CHANGE_CLASS}${CR_ID:+ · cr: $CR_ID}${SCAN_NOTE:+ · $SCAN_NOTE}${GATE_NOTE:+ · $GATE_NOTE}${HV_NOTE:+ · $HV_NOTE}$_EXEC_APPROVAL_SUFFIX${STEP_TIMES:+ · steps: $STEP_TIMES}"
+  _detail="$2${CHANGE_CLASS:+ · change: $CHANGE_CLASS}${CR_ID:+ · cr: $CR_ID}${SCAN_NOTE:+ · $SCAN_NOTE}${GATE_NOTE:+ · $GATE_NOTE}${MXB_LOG_NOTE:+ · $MXB_LOG_NOTE}${HV_NOTE:+ · $HV_NOTE}$_EXEC_APPROVAL_SUFFIX${STEP_TIMES:+ · steps: $STEP_TIMES}"
   printf '| %s | `%s` | %s | %s | %s |\n' \
     "$(date '+%Y-%m-%dT%H:%M:%S%z')" "$LOG_NAME" \
     "${GATE_STATE:-not-run}" "$1" "$_detail" >> "$BUILD_LOG"
@@ -1643,12 +1644,46 @@ if [ -x "$MXBUILD" ] && [ -x "$JAVA_EXE" ]; then
   MXB_WHY="${MXTK_MXBUILD_WHY:-}"
   step_done gate
 
+  # Keep the gate's full mxbuild output when the gate did not pass. The screen shows only the
+  # top lines (the failure detail is often in the tail), and the temp file behind
+  # mxtk_mxbuild_error_count is gone by now, so without this the evidence of a failed gate was
+  # lost (a field migration project lost the detail of a CE1613 this way). mxbuild prints output
+  # on a clean build too, so the log is written from the failure branches below (mxb_log_hint)
+  # and never for a pass, a delta-gate pass over pre-existing errors included. The one exception
+  # is a retry: the first attempt's output is the evidence of the infra exit, so a retry always
+  # leaves a log, with both attempts in it. One file per run, under .mpr-snapshots/.mxbuild-logs/,
+  # the newest 30 kept. The DOT in the name is load-bearing: restore-mpr.sh (no argument picks
+  # the newest) and snapshot-mpr.sh (keeps 5) glob `.mpr-snapshots/*/`, which skips dot dirs.
+  # Its project-relative path goes on screen and in the row.
+  MXB_LOG_REL=""
+  mxb_save_log() {
+    [ -z "$MXB_LOG_REL" ] || return 0
+    [ -n "$MXBUILD_OUT$MXTK_GATE_FIRST_OUT" ] || return 0
+    _MXB_LOG_DIR="$PROJECT_ROOT/.mpr-snapshots/.mxbuild-logs"
+    MXB_LOG_REL=".mpr-snapshots/.mxbuild-logs/$(date +%Y%m%d-%H%M%S)-$$.log"
+    if mkdir -p "$_MXB_LOG_DIR" 2>/dev/null && {
+      if [ -n "$MXTK_GATE_RETRY_NOTE" ]; then
+        printf '=== attempt 1 (exit %s, infra failure, retried) ===\n%s\n=== attempt 2 (final, exit %s) ===\n%s\n' \
+          "$MXTK_GATE_FIRST_EXIT" "$MXTK_GATE_FIRST_OUT" "$MXBUILD_EXIT" "$MXBUILD_OUT"
+      else
+        printf '%s\n' "$MXBUILD_OUT"
+      fi > "$PROJECT_ROOT/$MXB_LOG_REL"; } 2>/dev/null; then
+      MXB_LOG_NOTE="mxbuild log: $MXB_LOG_REL"
+      ls -t "$_MXB_LOG_DIR"/*.log 2>/dev/null | sed -n '31,$p' | while IFS= read -r _old; do rm -f "$_old"; done
+    else
+      MXB_LOG_REL=""
+    fi
+  }
+  mxb_log_hint() { mxb_save_log; [ -z "$MXB_LOG_REL" ] || echo "    full mxbuild output: $MXB_LOG_REL"; }
+  if [ -n "$MXTK_GATE_RETRY_NOTE" ]; then mxb_save_log; fi
+
   if [ -f "$ERRORS_FILE" ] && [ -s "$ERRORS_FILE" ]; then
     CE_COUNT=$(err_count "$ERRORS_FILE")
     if [ "$CE_COUNT" = "?" ]; then
       GATE_STATE="unverified"
       echo "  ⚠  mxbuild errors file could not be parsed — check manually."
       echo "$MXBUILD_OUT" | grep -v "^$\|icon\|Microsoft\|Assembly\|__" | head -10 || true
+      mxb_log_hint
     elif [ "$CE_COUNT" = "0" ] && [ "$MXBUILD_EXIT" -ne 0 ]; then
       # Non-empty errors file, 0 Error problems, NON-ZERO exit: mxbuild never checked the
       # model. The reason sits in errors[], which err_count does not read, e.g. (verbatim,
@@ -1662,6 +1697,7 @@ if [ -x "$MXBUILD" ] && [ -x "$JAVA_EXE" ]; then
       echo "  ✗ mxbuild exited $MXBUILD_EXIT and listed 0 model problems — it did NOT check the model."
       echo "    ${MXB_WHY:-no reason in errors[]; mxbuild output follows}"
       [ -z "$MXB_WHY" ] && { echo "$MXBUILD_OUT" | grep -v "^$\|icon\|Microsoft\|Assembly\|__" | tail -10 || true; }
+      mxb_log_hint
       echo "    A version mismatch is fixed by the matching mxbuild: ./mxcli setup mxbuild -p $MPR_BASE"
       echo "    (find_mxbuild prefers it once cached), or MXBUILD_PATH=<that mxbuild>."
     elif [ "$CE_COUNT" = "0" ]; then
@@ -1711,6 +1747,7 @@ if [ -x "$MXBUILD" ] && [ -x "$JAVA_EXE" ]; then
         rm -f "$ERRORS_FILE"
       else
         GATE_STATE="fail"
+        mxb_save_log
         CE_CODES=$(err_codes "$ERRORS_FILE")
         read -r NEW_COUNT NEW_CODES <<EOF
 $(err_report count "$ERRORS_FILE")
@@ -1801,6 +1838,7 @@ EOF
     echo "  ✗ mxbuild failed to run (exit $MXBUILD_EXIT) — gate could not verify the model."
     [ -n "$MXB_WHY" ] && echo "    mxbuild says: $MXB_WHY"
     echo "$MXBUILD_OUT" | grep -v "^$\|icon\|Microsoft\|Assembly\|__" | head -20 || true
+    mxb_log_hint
     # mxbuild CRASHED ON THE WRITTEN MODEL (field 2026-10-13, Mendix 11.14.0, mxcli v0.25.0): a
     # two-hop data source passed `check`, then mxbuild's loader died with no errors file. This
     # branch kept the write, the next exec printed "Baseline NOT measured" and wrote on top of a