repoview: include filter name in repr for debugging

mercurial/repoview.py

@@ -15,6 +15,7 b' from .node import nullrev'
 from . import (
     obsolete,
     phases,
+    pycompat,
     tags as tagsmod,
 )
 
@@ -232,6 +233,11 b' class repoview(object):'
             return self
         return self.unfiltered().filtered(name)
 
+    def __repr__(self):
+        return r'<%s:%s %r>' % (self.__class__.__name__,
+                                pycompat.sysstr(self.filtername),
+                                self.unfiltered())
+
     # everything access are forwarded to the proxied repo
     def __getattr__(self, attr):
         return getattr(self._unfilteredrepo, attr)