a102654e776e2ba96af731cac5b8cda1803fa3cb
markd
  Sat Dec 12 22:05:26 2020 -0800
make it more obvious that HAL screwed up and didn't set error message

diff --git src/hg/hgTracks/snakeTrack.c src/hg/hgTracks/snakeTrack.c
index 8a7bdf5..65eadb5 100644
--- src/hg/hgTracks/snakeTrack.c
+++ src/hg/hgTracks/snakeTrack.c
@@ -1342,31 +1342,31 @@
 char *aliasName = chromName;
 if (chromAlias)
    {
        if (differentWord(chromAlias, aliasName))
           aliasName = chromAlias;
    }
 
 boolean isPsl = sameString(tg->tdb->type, "pslSnake");
 
 // if we have a network error we want to put out a message about it
 struct errCatch *errCatch = errCatchNew();
 if (errCatchStart(errCatch))
     {
     char *fileName = trackDbSetting(tg->tdb, "bigDataUrl");
     char *otherSpecies = trackDbSetting(tg->tdb, "otherSpecies");
-    char *errString = "empty";
+    char *errString = "<HAL error message not set>";
     int handle = -1;
     if (!isPsl)
         {
         handle = halOpenLOD(fileName, &errString);
         if (handle < 0)
             {
             errAbort("HAL open error: %s\n", errString);
             goto out;
             }
         }
     boolean isPackOrFull = (tg->visibility == tvFull) || 
 	(tg->visibility == tvPack);
     hal_dup_type_t dupMode =  (isPackOrFull) ? HAL_QUERY_AND_TARGET_DUPS :
 	HAL_QUERY_DUPS;
     hal_seqmode_type_t needSeq = isPackOrFull && (winBaseCount < showSnpWidth) ? HAL_LOD0_SEQUENCE : HAL_NO_SEQUENCE;