From 759a5692b86ac4b12154379dba73319dff6ebe6d Mon Sep 17 00:00:00 2001
From: Brian Ward <bward@flatironinstitute.org>
Date: Thu, 25 Jan 2024 10:51:44 -0500
Subject: [PATCH] Fix pathfinder return

---
 src/stan/services/pathfinder/single.hpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/stan/services/pathfinder/single.hpp b/src/stan/services/pathfinder/single.hpp
index 4719a40e1e..9b19f0be29 100644
--- a/src/stan/services/pathfinder/single.hpp
+++ b/src/stan/services/pathfinder/single.hpp
@@ -821,10 +821,14 @@ inline auto pathfinder_lbfgs_single(
         lbfgs_ss.str("");
       }
       if (ReturnLpSamples) {
+        // we want to terminate multi-path pathfinder during these unrecoverable
+        // exceptions
         throw;
       } else {
         logger.error(e.what());
-        return error_codes::SOFTWARE;
+        return internal::ret_pathfinder<ReturnLpSamples>(
+            error_codes::SOFTWARE, Eigen::Array<double, Eigen::Dynamic, 1>(0),
+            Eigen::Matrix<double, Eigen::Dynamic, Eigen::Dynamic>(0, 0), 0);
       }
     }
   }