diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -1047,6 +1047,9 @@ def grep(ui, repo, pattern, *pats, **opt
             self.colstart = colstart
             self.colend = colend
 
+        def __hash__(self):
+            return hash((self.linenum, self.line))
+
         def __eq__(self, other):
             return self.line == other.line
 
diff --git a/mercurial/context.py b/mercurial/context.py
--- a/mercurial/context.py
+++ b/mercurial/context.py
@@ -34,6 +34,12 @@ class changectx(object):
     def __repr__(self):
         return "<changectx %s>" % str(self)
 
+    def __hash__(self):
+        try:
+            return hash(self._rev)
+        except AttributeError:
+            return id(self)
+
     def __eq__(self, other):
         try:
             return self._rev == other._rev
@@ -210,6 +216,12 @@ class filectx(object):
     def __repr__(self):
         return "<filectx %s>" % str(self)
 
+    def __hash__(self):
+        try:
+            return hash((self._path, self._fileid))
+        except AttributeError:
+            return id(self)
+
     def __eq__(self, other):
         try:
             return (self._path == other._path