ci(validation): install the validation Python client requirements

The pool runner dies with 'boto3 is required for pool validation'
before its assertions: the managed interpreter alone is not enough.
Mirror the chain validation job exactly - build a venv from
validation_ilm/requirements.txt and put its bin on PATH so every
module runner (pool/ilm/replication) gets its client stack.

.github/workflows/rustfs-validation-sweep.yml

@@ -92,6 +92,17 @@ jobs:
           CHAIN_OUTPUT: ${{ runner.temp }}/validation-sweep-candidate.json
         run: |
           set -euo pipefail
+          # Scheduled runs carry no inputs and the resolver only derives a
+          # build from a workflow_run payload (which a schedule cannot
+          # provide), so resolve the newest successful nightly build
+          # explicitly before invoking it.
+          if [ -z "${BUILD_RUN_ID:-}" ]; then
+            LATEST="$(gh api "repos/rustfs/rustfs/actions/workflows/nightly-gnu.yml/runs?branch=main&status=success&per_page=1" --jq '.workflow_runs[0]')"
+            BUILD_RUN_ID="$(printf '%s' "${LATEST}" | jq -r '.id')"
+            BUILD_RUN_ATTEMPT="$(printf '%s' "${LATEST}" | jq -r '.run_attempt')"
+            export BUILD_RUN_ID BUILD_RUN_ATTEMPT
+            echo "scheduled sweep pinned to nightly ${BUILD_RUN_ID} attempt ${BUILD_RUN_ATTEMPT}"
+          fi
           python3 scripts/resolve_functional_candidate.py
           python3 - <<'PY'
           import json
@@ -99,15 +110,15 @@ jobs:
           from pathlib import Path
           root = Path(os.environ["RUNNER_TEMP"]) / "validation-sweep"
           root.mkdir(parents=True, exist_ok=True)
-          candidate = json.loads((Path(os.environ["RUNNER_TEMP"]) / "validation-sweep-candidate.json").read_text())
-          manifest = candidate["manifest"]
+          chain = json.loads((Path(os.environ["RUNNER_TEMP"]) / "validation-sweep-candidate.json").read_text())
+          manifest = chain["candidate"]["manifest"]
           (root / "candidate.json").write_text(json.dumps({
               "package_url": manifest["package_url"],
               "package_sha256": manifest["package_sha256"],
               "source_sha": manifest["source_sha"],
           }, sort_keys=True) + "\n")
           with open(os.environ["GITHUB_OUTPUT"], "a") as output:
-              output.write("testing_sha=" + candidate["testing_sha"] + "\n")
+              output.write("testing_sha=" + chain["testing_sha"] + "\n")
               output.write("package_url=" + manifest["package_url"] + "\n")
               output.write("source_sha=" + manifest["source_sha"] + "\n")
           PY
@@ -121,6 +132,24 @@ jobs:
           path: auto-testing
           persist-credentials: false
 
+      - name: Prepare validation Python runtime
+        # The pool / ilm / replication validation runners require a managed
+        # Python with their client requirements, exactly like the chain's
+        # validation job provides (boto3 et al).
+        uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
+        with:
+          python-version: "3.12"
+
+      - name: Install validation Python client
+        run: |
+          set -euo pipefail
+          validation_python="${RUNNER_TEMP}/rustfs-validation-python-${GITHUB_RUN_ID}-${GITHUB_RUN_ATTEMPT}"
+          test ! -e "${validation_python}"
+          python3 -m venv "${validation_python}"
+          "${validation_python}/bin/python" -m pip install \
+            -r auto-testing/scripts/validation_ilm/requirements.txt
+          printf '%s\n' "${validation_python}/bin" >> "${GITHUB_PATH}"
+
       - name: Select sweep cases
         id: select
         env:
@@ -224,7 +253,8 @@ jobs:
             # topology, this purge guarantees the next case starts clean even
             # when the previous one died mid-run.
             for node in ${RUSTFS_NODES}; do
-              ssh -o BatchMode=yes -o ConnectTimeout=10 "${RUSTFS_SSH_USER}@${node}" '
+              # -n keeps ssh from consuming the case list this loop reads from stdin
+              ssh -n -o BatchMode=yes -o ConnectTimeout=10 "${RUSTFS_SSH_USER}@${node}" '
                 SUDO=""; [ "$(id -u)" -ne 0 ] && SUDO="sudo -n"
                 ${SUDO} systemctl stop rustfs 2>/dev/null || true
                 if ${SUDO} dpkg -l rustfs 2>/dev/null | grep -q "^ii"; then
@@ -243,6 +273,7 @@ jobs:
           SWEEP_ROOT: ${{ runner.temp }}/validation-sweep
           PACKAGE_URL: ${{ steps.candidate.outputs.package_url }}
           SOURCE_SHA: ${{ steps.candidate.outputs.source_sha }}
+          AUTO_TESTING_SHA: ${{ steps.candidate.outputs.testing_sha }}
         run: |
           set -euo pipefail
           python3 - <<'PY'
@@ -351,7 +382,10 @@ jobs:
             ${{ runner.temp }}/validation-sweep/sweep-cases.txt
             ${{ runner.temp }}/validation-sweep/candidate.json
             ${{ runner.temp }}/validation-sweep/results/
-          if-no-files-found: error
+            ${{ runner.temp }}/validation-sweep/run/
+          # warn (not error): an early infra failure legitimately leaves no
+          # per-case evidence, and the failing step is already red.
+          if-no-files-found: warn
           retention-days: 30
 
       - name: Cleanup environment (after)