Draft: expose required Hydra PMI_FD handling for MANA checkpoint/restart

contrib/dmtcp-patches/0001-ipc-skip-socket-scan-when-PMI_FD-is-set.patch

@@ -0,0 +1,12 @@
+--- a/src/plugin/ipc/socket/socketconnlist.cpp
++++ b/src/plugin/ipc/socket/socketconnlist.cpp
+@@ -257,7 +257,8 @@
+
+   if ((getenv("SLURM_JOBID")) ||
+       (getenv("SLURM_JOB_ID")) ||
+-      (getenv("HYDI_CONTROL_FD"))) {
++      (getenv("HYDI_CONTROL_FD")) ||
++      (getenv("PMI_FD"))) {
+     return;
+   }
+

contrib/dmtcp-patches/README.md

@@ -0,0 +1,13 @@
+# Required Hydra `PMI_FD` downstream patch
+
+This directory records the exact DMTCP source delta required by the contributor's validated MANA/MPICH/Hydra environment.
+
+Apply locally for testing:
+
+```bash
+bash contrib/dmtcp-patches/apply.sh
+```
+
+The helper modifies only the checked-out DMTCP submodule source and is idempotent. The resulting dirty submodule contents are for validation only and must be restored before committing this MANA draft branch.
+
+This draft intentionally asks the MANA maintainers to decide whether the final solution should be a temporary downstream patch, an in-tree MANA compatibility fix, a direct DMTCP contribution, or another design.

contrib/dmtcp-patches/apply.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -euo pipefail
+mana_root="$(cd "$(dirname "$0")/../.." && pwd)"
+patch="$mana_root/contrib/dmtcp-patches/0001-ipc-skip-socket-scan-when-PMI_FD-is-set.patch"
+source_file="$(git -C "$mana_root/dmtcp" grep -l 'HYDI_CONTROL_FD' -- '*socketconnlist.cpp' | head -n 1)"
+[[ -n "$source_file" ]] || { echo "ERROR: socketconnlist.cpp not found" >&2; exit 1; }
+if git -C "$mana_root/dmtcp" grep -q 'getenv("PMI_FD")' -- "$source_file"; then
+  echo "PMI_FD is already present in dmtcp/$source_file"
+  exit 0
+fi
+git -C "$mana_root/dmtcp" apply "$patch"
+git -C "$mana_root/dmtcp" diff --check
+echo "Applied $patch to the local DMTCP submodule checkout."
+echo "Do not commit dirty submodule contents in this draft PR."