test: harden parallels all-os smoke harness

scripts/e2e/parallels-linux-smoke.sh

@@ -17,6 +17,7 @@ MAIN_TGZ_DIR="$(mktemp -d)"
 MAIN_TGZ_PATH=""
 SERVER_PID=""
 RUN_DIR="$(mktemp -d /tmp/openclaw-parallels-linux.XXXXXX)"
+BUILD_LOCK_DIR="${TMPDIR:-/tmp}/openclaw-parallels-build.lock"
 
 TIMEOUT_SNAPSHOT_S=180
 TIMEOUT_BOOTSTRAP_S=600
@@ -260,16 +261,41 @@ else:
 PY
 }
 
+acquire_build_lock() {
+  local owner_pid=""
+  while ! mkdir "$BUILD_LOCK_DIR" 2>/dev/null; do
+    if [[ -f "$BUILD_LOCK_DIR/pid" ]]; then
+      owner_pid="$(cat "$BUILD_LOCK_DIR/pid" 2>/dev/null || true)"
+      if [[ -n "$owner_pid" ]] && ! kill -0 "$owner_pid" >/dev/null 2>&1; then
+        warn "Removing stale Parallels build lock"
+        rm -rf "$BUILD_LOCK_DIR"
+        continue
+      fi
+    fi
+    sleep 1
+  done
+  printf '%s\n' "$$" >"$BUILD_LOCK_DIR/pid"
+}
+
+release_build_lock() {
+  if [[ -d "$BUILD_LOCK_DIR" ]]; then
+    rm -rf "$BUILD_LOCK_DIR"
+  fi
+}
+
 ensure_current_build() {
   local head build_commit
+  acquire_build_lock
   head="$(git rev-parse HEAD)"
   build_commit="$(current_build_commit)"
   if [[ "$build_commit" == "$head" ]]; then
+    release_build_lock
     return
   fi
   say "Build dist for current head"
   pnpm build
   build_commit="$(current_build_commit)"
+  release_build_lock
   [[ "$build_commit" == "$head" ]] || die "dist/build-info.json still does not match HEAD after build"
 }