Ignore single-zero-sample trace on no runtime..

piker/tsp/_anal.py

@@ -276,7 +276,15 @@ def get_null_segs(
         absi_zdiff: np.ndarray = np.diff(absi_zeros)
 
         if zero_t.size < 2:
-            breakpoint()
+            try:
+                breakpoint()
+            except RuntimeError:
+                # XXX, if greenback not active from
+                # piker store ldshm cmd..
+                log.exception(
+                    "Can't debug single-sample null!\n"
+                )
+
             return None
 
         # scan for all frame-indices where the