From 31b5a1fe9593d7d5d1064433378315f8f8a4f450 Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Thu, 7 Feb 2019 11:27:20 +0000
Subject: [PATCH] pock: Report `duplicate label' as an expected error.

It shouldn't result in a backtrace.
---
 pock | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pock b/pock
index 053cb36..3d9f66b 100644
--- a/pock
+++ b/pock
@@ -662,7 +662,7 @@ class PrimeProof (object):
 
     ## If the label is already taken then we have a problem.
     if step.label in me._steps:
-      raise ValueError('duplicate label `%s\'' % step.label)
+      raise ExpectedError('duplicate label `%s\'' % step.label)
 
     ## Store the proof step.
     me._pmap[step.p] = step.label
-- 
2.11.0