need null check, if match is cancelled

Author: ryanfleury

src/dbg_info/dbg_info.c

@@ -1564,19 +1564,22 @@ di_match_artifact_create(String8 key, B32 *cancel_signal, B32 *retry_out, U64 *g
   lane_sync();
 
   //- rjf: pick match
-  DI_Match match = {0};
-  for EachIndex(idx, lane_count())
-  {
-    if(lane_matches[idx].idx != 0)
+  DI_Match match = {0};
+  if(lane_matches != 0)
+  {
+    for EachIndex(idx, lane_count())
     {
-      match = lane_matches[idx];
-      if(di_key_match(di_key_zero(), preferred_key) || di_key_match(match.key, preferred_key))
-      {
-        break;
-      }
+      if(lane_matches[idx].idx != 0)
+      {
+        match = lane_matches[idx];
+        if(di_key_match(di_key_zero(), preferred_key) || di_key_match(match.key, preferred_key))
+        {
+          break;
+        }
+      }
     }
-  }
-  
+  }
+  
   //- rjf: package as artifact
   AC_Artifact artifact = {0};
   {