T44 #4875: the pmat hunt runs one hop from the pick, after Coverage Nightly

.github/workflows/beat-speed-nightly.yml

@@ -31,17 +31,13 @@
 name: BEAT Speed (nightly)
 
 on:
-  schedule:
-    # SHIFTED so it actually runs at night (#3292). GitHub dispatches
-    # schedule events 3h51m-6h49m late on this account (28 runs, 10
-    # workflows, 3 nights, zero on time), so a 05:45 cron fired mid-
-    # morning and the nightly tier occupied 06:49-14:14 UTC — the
-    # working day, competing with PR traffic for the same runners.
-    # Cron is set ~5h EARLY so the delayed dispatch lands near 05:45 UTC.
-    # This is CALIBRATION AGAINST A MOVING TARGET: the delay varies by
-    # ~3h and is growing. The durable fix is a fleet-side timer calling
-    # `gh workflow run` (#3292); until then, re-measure before trusting.
-    - cron: "45 0 * * *"   # 00:45 UTC -> lands ~05:45 UTC
+  # Chained, not scheduled (T44, #4686): this producer measures the night's
+  # C that "Nightly pick" pinned at nightly/<night>, never main's head at
+  # whatever hour GitHub got round to creating a scheduled run.
+  workflow_run:
+    workflows: ["Nightly pick"]
+    types: [completed]
+    branches: [main]
   workflow_dispatch:
 
 jobs:
@@ -79,6 +75,12 @@ jobs:
       BEAT_LOG: ${{ github.workspace }}/beat-speed-measurements.log
     steps:
       - uses: actions/checkout@v7
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run'
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
 
       # PERF-031 measurement-environment receipt.
       #

.github/workflows/book-contracts.yml

@@ -35,9 +35,14 @@ on:
       - ".github/workflows/book-contracts.yml"
   # #3676 rule 3 (scripts/check_workflow_path_filters.sh): a path filter is a
   # claim that nothing outside these paths can break this gate; the nightly run
-  # re-checks the claim every day. Set ~5h early for the dispatch delay (#3292).
-  schedule:
-    - cron: '45 22 * * *'
+  # re-checks the claim every night, on the night's C.
+  # Chained, not scheduled (T44, #4686): this producer measures the night's
+  # C that "Nightly pick" pinned at nightly/<night>, never main's head at
+  # whatever hour GitHub got round to creating a scheduled run.
+  workflow_run:
+    workflows: ["Nightly pick"]
+    types: [completed]
+    branches: [main]
 
 
 # #3676: no concurrency group meant every superseded PR push ran the ~18 min
@@ -62,6 +67,12 @@ jobs:
     runs-on: [self-hosted, Linux, X64, clean-room]
     steps:
       - uses: actions/checkout@v7
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run'
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
       - uses: dtolnay/rust-toolchain@stable
       # NO rust-cache: cache-bin false was never the fix.
       #
@@ -106,6 +117,12 @@ jobs:
     needs: chapter-examples-compile
     steps:
       - uses: actions/checkout@v7
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run'
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
       - uses: dtolnay/rust-toolchain@stable
       # NO rust-cache: cache-bin false was never the fix.
       #
@@ -157,6 +174,12 @@ jobs:
     runs-on: [self-hosted, Linux, X64, clean-room]
     steps:
       - uses: actions/checkout@v7
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run'
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
       - uses: dtolnay/rust-toolchain@stable
       # NO rust-cache: cache-bin false was never the fix.
       #
@@ -189,6 +212,12 @@ jobs:
     runs-on: [self-hosted, Linux, X64, clean-room]
     steps:
       - uses: actions/checkout@v7
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run'
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
       - name: Every chapter has a contract
         run: |
           FAIL=0
@@ -249,6 +278,12 @@ jobs:
     runs-on: [self-hosted, Linux, X64, clean-room]
     steps:
       - uses: actions/checkout@v7
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run'
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
       - name: No legacy imports in chapter examples
         run: |
           FAIL=0
@@ -290,6 +325,12 @@ jobs:
     runs-on: [self-hosted, Linux, X64, clean-room]
     steps:
       - uses: actions/checkout@v7
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run'
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
       - name: No dead links in SUMMARY.md
         run: |
           FAIL=0

.github/workflows/book.yml

@@ -51,9 +51,14 @@ on:
       - "crates/apr-cli/src/tool_commands.rs"
   # #3676 rule 3 (scripts/check_workflow_path_filters.sh): a path filter is a
   # claim that nothing outside these paths can break this gate; the nightly run
-  # re-checks the claim every day. Set ~5h early for the dispatch delay (#3292).
-  schedule:
-    - cron: '30 22 * * *'
+  # re-checks the claim every night, on the night's C.
+  # Chained, not scheduled (T44, #4686): this producer measures the night's
+  # C that "Nightly pick" pinned at nightly/<night>, never main's head at
+  # whatever hour GitHub got round to creating a scheduled run.
+  workflow_run:
+    workflows: ["Nightly pick"]
+    types: [completed]
+    branches: [main]
 
 permissions:
   contents: read
@@ -75,6 +80,12 @@ jobs:
     runs-on: [self-hosted, Linux, X64, clean-room]
     steps:
       - uses: actions/checkout@v7
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run'
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
 
       # Self-hosted (#3073): tools go into this run's private $RUNNER_TEMP, never a $HOME path that every
       # runner on the box execs from (the aprender#2353 race; check_cargo_install_private_root.sh enforces

.github/workflows/conleche-nightly.yml

@@ -21,10 +21,13 @@
 name: conleche-nightly
 
 on:
-  schedule:
-    # 21:23 UTC -> lands ~02:23 UTC. GitHub dispatches schedules ~5h late on this account (#3292); the slot is
-    # free and clear of guards-nightly (21:47) and cuda-nightly (20:30).
-    - cron: '23 21 * * *'
+  # Chained, not scheduled (T44, #4686): this producer measures the night's
+  # C that "Nightly pick" pinned at nightly/<night>, never main's head at
+  # whatever hour GitHub got round to creating a scheduled run.
+  workflow_run:
+    workflows: ["Nightly pick"]
+    types: [completed]
+    branches: [main]
   workflow_dispatch:
 
 concurrency:
@@ -49,6 +52,12 @@ jobs:
       - uses: actions/checkout@v7
         with:
           fetch-depth: 1
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run'
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
       - name: Verdict case table (the classifier this job trusts)
         run: bash crates/aprender-contracts-staging/lean/conleche.sh --self-test
       - name: Pinned elan in the job's own directory (sha256-checked, never a host install)

.github/workflows/coverage-nightly.yml

@@ -21,17 +21,13 @@ name: Coverage Nightly
 # measurement ever worked.
 
 on:
-  schedule:
-    # SHIFTED so it actually runs at night (#3292). GitHub dispatches
-    # schedule events 3h51m-6h49m late on this account (28 runs, 10
-    # workflows, 3 nights, zero on time), so a 03:00 cron fired mid-
-    # morning and the nightly tier occupied 06:49-14:14 UTC — the
-    # working day, competing with PR traffic for the same runners.
-    # Cron is set ~5h EARLY so the delayed dispatch lands near 03:00 UTC.
-    # This is CALIBRATION AGAINST A MOVING TARGET: the delay varies by
-    # ~3h and is growing. The durable fix is a fleet-side timer calling
-    # `gh workflow run` (#3292); until then, re-measure before trusting.
-    - cron: '0 22 * * *'   # 22:00 UTC -> lands ~03:00 UTC
+  # Chained, not scheduled (T44, #4686): this producer measures the night's
+  # C that "Nightly pick" pinned at nightly/<night>, never main's head at
+  # whatever hour GitHub got round to creating a scheduled run.
+  workflow_run:
+    workflows: ["Nightly pick"]
+    types: [completed]
+    branches: [main]
   workflow_dispatch: {}
   # #3676: no v* tag trigger here. The release tag's coverage is owned by ci.yml
   # (`coverage_on: tag`, which sovereign-ci's gate requires on a tag push), so a tag
@@ -109,6 +105,12 @@ jobs:
       - uses: actions/checkout@v7
         with:
           clean: false
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run'
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
 
       # Provision cargo-llvm-cov WITHOUT touching ~/.cargo/bin (#2353).
       #

.github/workflows/cuda-nightly.yml

@@ -44,17 +44,13 @@ name: CUDA Nightly (GPU QLoRA falsifiers)
 # without deleting the workflow.
 
 on:
-  schedule:
-    # SHIFTED so it actually runs at night (#3292). GitHub dispatches
-    # schedule events 3h51m-6h49m late on this account (28 runs, 10
-    # workflows, 3 nights, zero on time), so a 01:30 cron fired mid-
-    # morning and the nightly tier occupied 06:49-14:14 UTC — the
-    # working day, competing with PR traffic for the same runners.
-    # Cron is set ~5h EARLY so the delayed dispatch lands near 01:30 UTC.
-    # This is CALIBRATION AGAINST A MOVING TARGET: the delay varies by
-    # ~3h and is growing. The durable fix is a fleet-side timer calling
-    # `gh workflow run` (#3292); until then, re-measure before trusting.
-    - cron: "30 20 * * *"   # 20:30 UTC -> lands ~01:30 UTC
+  # Chained, not scheduled (T44, #4686): this producer measures the night's
+  # C that "Nightly pick" pinned at nightly/<night>, never main's head at
+  # whatever hour GitHub got round to creating a scheduled run.
+  workflow_run:
+    workflows: ["Nightly pick"]
+    types: [completed]
+    branches: [main]
   workflow_dispatch:
     inputs:
       silicon:
@@ -165,7 +161,7 @@ jobs:
             # NOT_RUN is not PASS.
             mkdir -p "$PERF041_OUT"
             printf '{"host":"%s","status":"NOT_RUN","reason":"yield to training (%s MiB, %s procs)","started_utc":"%s","commit":"%s","exit":null,"max_m":null,"cc":null,"sha256":null}\n' \
-              "${{ matrix.name }}" "${used:-?}" "${procs:-?}" "$(date -u +%Y-%m-%dT%H:%M:%SZ)" "${{ github.sha }}" \
+              "${{ matrix.name }}" "${used:-?}" "${procs:-?}" "$(date -u +%Y-%m-%dT%H:%M:%SZ)" "${{ github.event.workflow_run.head_sha || github.sha }}" \
               > "$PERF041_OUT/marker.json"
             echo "proceed=false" >> "$GITHUB_OUTPUT"; exit 0
           fi
@@ -174,11 +170,20 @@ jobs:
       - uses: actions/checkout@v7
         if: steps.decide.outputs.proceed == 'true'
 
-      # The first thing gx10 does once it has a tree. NOT before `decide` and
-      # NOT before the checkout, for the reason the comment below spells out:
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run' && (steps.decide.outputs.proceed == 'true')
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
+
+      # The first thing this job does once its tree is C (the step above). NOT before
+      # `decide`, and NOT before the checkout, for the reason the comment below spells out:
       # on a yield night there is no working tree, so a step that `bash`es a
       # repo path exits 127 and turns a deliberately-yielded night RED. It
       # carries the same `if:` as the checkout it follows.
+      # It comes AFTER the C step, not between the checkout and it: there it
+      # ran main's head's copy of the preflight, so it did not judge C's own.
       #
       # gx10 is the box where run 34448908554 died on `gh: command not found`
       # after a 21 MB CUDA build. Everything below this line assumes cargo,
@@ -802,6 +807,12 @@ jobs:
       CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_RUNNER: flock -E 175 -w 600 /run/lock/fleet-gpu/gpu.lock
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run'
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
 
       - name: Put the runner's Rust toolchain on PATH
         run: echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"

.github/workflows/examples-nightly.yml

@@ -9,17 +9,13 @@
 name: examples-nightly
 
 on:
-  schedule:
-    # SHIFTED so it actually runs at night (#3292). GitHub dispatches
-    # schedule events 3h51m-6h49m late on this account (28 runs, 10
-    # workflows, 3 nights, zero on time), so a 03:30 cron fired mid-
-    # morning and the nightly tier occupied 06:49-14:14 UTC — the
-    # working day, competing with PR traffic for the same runners.
-    # Cron is set ~5h EARLY so the delayed dispatch lands near 03:30 UTC.
-    # This is CALIBRATION AGAINST A MOVING TARGET: the delay varies by
-    # ~3h and is growing. The durable fix is a fleet-side timer calling
-    # `gh workflow run` (#3292); until then, re-measure before trusting.
-    - cron: '30 22 * * *'   # 22:30 UTC -> lands ~03:30 UTC
+  # Chained, not scheduled (T44, #4686): this producer measures the night's
+  # C that "Nightly pick" pinned at nightly/<night>, never main's head at
+  # whatever hour GitHub got round to creating a scheduled run.
+  workflow_run:
+    workflows: ["Nightly pick"]
+    types: [completed]
+    branches: [main]
   workflow_dispatch:
     inputs:
       filter:
@@ -41,6 +37,12 @@ jobs:
     timeout-minutes: 300
     steps:
       - uses: actions/checkout@v7
+      - name: Measure the night's C, not main's head (T44)
+        if: github.event_name == 'workflow_run'
+        env:
+          NIGHTLY_PICK_AT: ${{ github.event.workflow_run.created_at }}
+          NIGHTLY_PICK_CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+        run: bash scripts/release/nightly_c_checkout.sh --at "$NIGHTLY_PICK_AT" --pick-conclusion "$NIGHTLY_PICK_CONCLUSION"
 
       - name: dogfood_examples.sh case table (hermetic, scratch workspace)
         run: bash scripts/dogfood_examples.sh --selftest