bisect-kit: revise "too much skip" error messages

BUG=b:124841028
TEST=None

Change-Id: Ie527a080df7e67c2df4ad3e6a2436218e293a694
Reviewed-on: https://chromium-review.googlesource.com/1514197
Commit-Ready: Kuang-che Wu <kcwu@chromium.org>
Tested-by: Kuang-che Wu <kcwu@chromium.org>
Reviewed-by: Chung-yih Wang <cywang@chromium.org>
diff --git a/bisect_kit/cli.py b/bisect_kit/cli.py
index cea4e28..b13f7f1 100644
--- a/bisect_kit/cli.py
+++ b/bisect_kit/cli.py
@@ -503,8 +503,10 @@
           current_state = self.states.get(idx)
           if current_state['skip'] > (
               current_state['old'] + current_state['new'] + 1) * 5:
-            message = 'too much "skip" for rev=%r' % rev
-            raise errors.UnableToProceed(message)
+            raise errors.UnableToProceed(
+                'something wrong, '
+                'unable to evalulate rev=%r (skip) %d times' %
+                (rev, current_state['skip']))
 
         self.strategy.show_summary()