[mc] Fix segfault when displaying SIMCALL_MUTEX_LOCK

diff --git a/src/mc/mc_request.cpp b/src/mc/mc_request.cpp
index 4dfc427..4503597 100644 (file)
--- a/src/mc/mc_request.cpp
+++ b/src/mc/mc_request.cpp
@@ -650,7 +650,7 @@ char *MC_request_get_dot_output(smx_simcall_t req, int value)
     break;
 
   case SIMCALL_MUTEX_LOCK:
-    label = bprintf("[(%lu)] Mutex LOCK", req->issuer->pid);
+    label = bprintf("[(%lu)] Mutex LOCK", issuer->pid);
     break;
 
   case SIMCALL_MC_RANDOM: