diff -r c2a0bc6412db -r 4fe63b573791 mercurial/revlog.py
--- a/mercurial/revlog.py	Sat Oct 13 01:55:40 2018 -0700
+++ b/mercurial/revlog.py	Fri Nov 02 14:24:29 2018 -0400
@@ -2207,7 +2207,7 @@
     def emitrevisions(self, nodes, nodesorder=None, revisiondata=False,
                       assumehaveparentrevisions=False,
                       deltamode=repository.CG_DELTAMODE_STD):
-        if nodesorder not in ('nodes', 'storage', None):
+        if nodesorder not in ('nodes', 'storage', 'linear', None):
             raise error.ProgrammingError('unhandled value for nodesorder: %s' %
                                          nodesorder)