From 0ca5e7207ea3433f7fc5dd76da0604396a55d97a Mon Sep 17 00:00:00 2001
From: Nikolaj Bjorner <nbjorner@microsoft.com>
Date: Sun, 2 Jan 2022 11:35:55 -0800
Subject: [PATCH] #5746

---
 src/solver/check_sat_result.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/solver/check_sat_result.cpp b/src/solver/check_sat_result.cpp
index 71bd24747..d29e0f2bd 100644
--- a/src/solver/check_sat_result.cpp
+++ b/src/solver/check_sat_result.cpp
@@ -21,7 +21,8 @@ Notes:
 void check_sat_result::set_reason_unknown(event_handler& eh) {
     switch (eh.caller_id()) {
     case UNSET_EH_CALLER: 
-        set_reason_unknown("unclassifed exception");
+        if (reason_unknown() == "")
+            set_reason_unknown("unclassifed exception");
         break;
     case CTRL_C_EH_CALLER:
         set_reason_unknown("interrupted from keyboard");