# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@fb.com>
# Date 2014-05-28 22:53:34
# Node ID b6eb56a9335d58ed2542de450f7eb71c7d9551f2
# Parent  6eaa71b2a3cca686aa4d47909171d1c208a810e6

bundle2: introduce a ``params`` attribute to BundleValueError

We'll first use it for unsupported mandatory parameters on parts.

diff --git a/mercurial/error.py b/mercurial/error.py
--- a/mercurial/error.py
+++ b/mercurial/error.py
@@ -100,13 +100,15 @@ class PushRaced(RuntimeError):
 
 # bundle2 related errors
 class BundleValueError(ValueError):
-    """error raised when bundle2 cannot be processed
-
-    Current main usecase is unsupported part types."""
+    """error raised when bundle2 cannot be processed"""
 
-    def __init__(self, parttype):
+    def __init__(self, parttype, params=()):
         self.parttype = parttype
-        super(BundleValueError, self).__init__(parttype)
+        self.params = params
+        msg = parttype
+        if self.params:
+            msg = '%s - %s' % (msg, ', '.join(self.params))
+        super(BundleValueError, self).__init__(msg)
 
 class ReadOnlyPartError(RuntimeError):
     """error raised when code tries to alter a part being generated"""