.

wcfs/wcfs_test.py

@@ -640,13 +640,15 @@ def watch(w, zf, at):   # XXX -> ?
 
     pin = w._pinAt(zf, at)
 
+    print('\n%s\n%s' % (pin_prev, pin))
+
     for blk in set(pin_prev.keys()).union(pin.keys()):
         # blk ∉ pin_prev,   blk ∉ pin       -> cannot happen
         assert (blk in pin_prev) or (blk in pin)
 
         # blk ∉ pin_prev,   blk ∈ pin       -> cannot happen
-        if at_prev is not None:
-            if blk not in pin_prev and blk in pin:
+        if blk not in pin_prev and blk in pin:
+            if at_prev is not None:
                 assert False, '#%d pinned %s; not pinned %s' % (t.hat(at_prev), t.hat(at))
 
         # blk ∈ pin_prev,   blk ∉ pin       -> unpin to head
@@ -659,6 +661,7 @@ def watch(w, zf, at):   # XXX -> ?
             if pin_prev[blk] == pin[blk]:
                 del pin[blk]    # would need to pin to what it is already pinned
 
+    print('-> %s' % pin)
 
     # {} blk -> at that have to be pinned
     # XXX also check that head/file[blk] is in cache - else no need to pin