From 7dc4e17e0cb1e1d42c98013181b2159cc7d76ca8 Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Sat, 14 Jun 2025 12:57:01 -0400
Subject: [PATCH] fix compilation with MPI STUBS

---
 src/library.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/library.cpp b/src/library.cpp
index 5b16985183..78ff2cf25a 100644
--- a/src/library.cpp
+++ b/src/library.cpp
@@ -1277,7 +1277,9 @@ If LAMMPS was compiled with MPI_STUBS, this function returns -1.
 int lammps_get_mpi_comm(void *handle)
 {
 #ifdef MPI_STUBS
-  const auto mesg = fmt::format("ERROR: {}(): Invalid LAMMPS handle\n", FNERR);
+  LAMMPS *lmp = nullptr;
+  const auto mesg = fmt::format("ERROR: {}(): No MPI communicator conversion possible "
+                                "with MPI STUBS\n", FNERR);
   STORE_ERROR_MESSAGE(lmp, mesg);
   return -1;
 #else