fix(bench): pipe bake.log to shared volume, print on failure

Author: nikolay-e

.github/workflows/bench-sweep.yml

@@ -101,20 +101,21 @@ jobs:
           docker pull ghcr.io/nikolay-e/treemapper-bench:latest
           nohup bash -c '
             mkdir -p /data/bench_repos
+            BAKE_LOG=/data/bench_repos/bake.log
             if docker run --rm \
               -v /data/bench_repos:/cache/contextbench_repos \
               -e BAKE_PARALLELISM=16 \
               ghcr.io/nikolay-e/treemapper-bench:latest \
               python /app/scripts/bake_bench_cache.py /cache/contextbench_repos \
-              >> /var/log/bake.log 2>&1; then
+              >> "\${BAKE_LOG}" 2>&1; then
               touch /data/bench_repos/.ready
-              echo "[bake] OK at \$(date -u +%Y-%m-%dT%H:%M:%SZ)" >> /var/log/bake.log
+              echo "[bake] OK at \$(date -u +%Y-%m-%dT%H:%M:%SZ)" >> "\${BAKE_LOG}"
             else
               rc=\$?
               touch /data/bench_repos/.bake_failed
-              echo "[bake] FAILED rc=\${rc} at \$(date -u +%Y-%m-%dT%H:%M:%SZ)" >> /var/log/bake.log
+              echo "[bake] FAILED rc=\${rc} at \$(date -u +%Y-%m-%dT%H:%M:%SZ)" >> "\${BAKE_LOG}"
             fi
-          ' >> /var/log/bake.log 2>&1 &
+          ' &
           curl -sL -o /tmp/runner.tar.gz \
             "https://github.com/actions/runner/releases/download/v${RUNNER_VER}/actions-runner-linux-x64-${RUNNER_VER}.tar.gz"
           for N in 1 2 3 4; do
@@ -269,7 +270,9 @@ jobs:
         run: |
           while true; do
             if [ -f /cache/contextbench_repos/.bake_failed ]; then
-              echo "ERROR: bake job failed — sweep aborted. Check /var/log/bake.log on the runner host."
+              echo "=== BAKE FAILED — full log ==="
+              cat /cache/contextbench_repos/bake.log || echo "(bake.log not found)"
+              echo "=== end of bake.log ==="
               exit 1
             fi
             if [ -f /cache/contextbench_repos/.ready ]; then