From 9f4fdd09fa0f7f6875e4e620c27d306e5daa9c27 Mon Sep 17 00:00:00 2001
From: Lisa Julia Nebel <lisa.nebel@dr-blatt.de>
Date: Sun, 29 Sep 2024 22:30:01 +0200
Subject: [PATCH] Throw an error if the status "lastStepFailed" in prepareStep
 of BlackoilModel is not the same across all processes

---
 opm/simulators/flow/BlackoilModel.hpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/opm/simulators/flow/BlackoilModel.hpp b/opm/simulators/flow/BlackoilModel.hpp
index 1d62a68c8..a4443dcdb 100644
--- a/opm/simulators/flow/BlackoilModel.hpp
+++ b/opm/simulators/flow/BlackoilModel.hpp
@@ -272,7 +272,11 @@ namespace Opm {
             Dune::Timer perfTimer;
             perfTimer.start();
             // update the solution variables in the model
-            if ( timer.lastStepFailed() ) {
+            int lastStepFailed = timer.lastStepFailed();
+            if (grid_.comm().size() > 1 && lastStepFailed != grid_.comm().min(lastStepFailed)) {
+                OPM_THROW(std::runtime_error, fmt::format("Misalignment of the parallel simulation run in prepareStep - the previous step succeeded on rank {} but failed on the other ranks.", grid_.comm().rank()));
+            }
+            if ( lastStepFailed ) {
                 simulator_.model().updateFailed();
             } else {
                 simulator_.model().advanceTimeLevel();