From 290c4b6b55b1ae9d3f9cf7866415de862f9435be Mon Sep 17 00:00:00 2001
From: Nesterov Alexander <nesterov.alexander@outlook.com>
Date: Fri, 20 Jun 2025 16:04:40 +0200
Subject: [PATCH] Fix MPI environment variable list size

---
 modules/core/util/src/util.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/modules/core/util/src/util.cpp b/modules/core/util/src/util.cpp
index ea76a08be..9d4c01a3d 100644
--- a/modules/core/util/src/util.cpp
+++ b/modules/core/util/src/util.cpp
@@ -28,7 +28,10 @@ int ppc::util::GetNumThreads() {
   return 1;
 }
 
-constexpr std::array<std::string_view, 13> kMpiEnvVars = {
+// List of environment variables that signal the application is running under
+// an MPI launcher. The array size must match the number of entries to avoid
+// looking up empty environment variable names.
+constexpr std::array<std::string_view, 10> kMpiEnvVars = {
     "OMPI_COMM_WORLD_SIZE", "OMPI_UNIVERSE_SIZE", "PMI_SIZE",     "PMI_RANK",   "PMI_FD",
     "HYDRA_CONTROL_FD",     "PMIX_RANK",          "SLURM_PROCID", "MSMPI_RANK", "MSMPI_LOCALRANK"};