probe: runner capability diagnostics

.gitea/workflows/probe.yml

@@ -0,0 +1,27 @@
+name: probe
+on: [push]
+jobs:
+    probe:
+        runs-on: ubuntu-latest
+        steps:
+            # actions/checkout v4.2.2, 2026-02-22
+            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+            - run: |
+                  set -x
+                  id
+                  pwd
+                  cat /etc/hostname
+                  docker version || true
+                  docker info --format '{{.Driver}} {{.ServerVersion}}' || true
+                  echo "--- mountinfo ---"
+                  cat /proc/self/mountinfo
+                  echo "--- inspect self by hostname ---"
+                  docker inspect "$(cat /etc/hostname)" --format '{{json .Mounts}}' || true
+                  echo "--- bind mount probe ---"
+                  docker run --rm -v "$PWD:/work" -w /work alpine:3 ls -la /work | head -20 || true
+                  echo "--- named volume probe ---"
+                  VOL=$(docker inspect "$(cat /etc/hostname)" --format '{{range .Mounts}}{{if eq .Destination "/workspace"}}{{.Name}}{{end}}{{end}}' || true)
+                  echo "VOL=$VOL"
+                  docker run --rm -v "$VOL:/workspace" -w "$PWD" alpine:3 ls -la . | head -20 || true
+                  echo "--- shm in docker run default ---"
+                  docker run --rm alpine:3 df -h /dev/shm || true