--- a/mercurial/formatter.py	Thu Feb 15 17:14:45 2018 +0530
+++ b/mercurial/formatter.py	Sat Feb 17 18:09:56 2018 +0900
@@ -291,7 +291,7 @@
         self._out = out
         self._out.write("%s = [\n" % self._topic)
     def _showitem(self):
-        self._out.write('    %s,\n' % pycompat.sysbytes(repr(self._item)))
+        self._out.write('    %s,\n' % pycompat.byterepr(self._item))
     def end(self):
         baseformatter.end(self)
         self._out.write("]\n")

--- a/mercurial/pycompat.py	Thu Feb 15 17:14:45 2018 +0530
+++ b/mercurial/pycompat.py	Sat Feb 17 18:09:56 2018 +0900
@@ -85,6 +85,7 @@
         sysargv = list(map(os.fsencode, sys.argv))
 
     bytechr = struct.Struct('>B').pack
+    byterepr = b'%r'.__mod__
 
     class bytestr(bytes):
         """A bytes which mostly acts as a Python 2 str
@@ -277,6 +278,7 @@
     import cStringIO
 
     bytechr = chr
+    byterepr = repr
     bytestr = str
     iterbytestr = iter
     maybebytestr = identity

--- a/mercurial/smartset.py	Thu Feb 15 17:14:45 2018 +0530
+++ b/mercurial/smartset.py	Sat Feb 17 18:09:56 2018 +0900
@@ -35,7 +35,7 @@
     elif callable(r):
         return r()
     else:
-        return pycompat.sysbytes(repr(r))
+        return pycompat.byterepr(r)
 
 def _typename(o):
     return pycompat.sysbytes(type(o).__name__).lstrip('_')
@@ -400,7 +400,7 @@
             # We fallback to the sorted version for a stable output.
             if self._ascending is not None:
                 l = self._asclist
-            s = pycompat.sysbytes(repr(l))
+            s = pycompat.byterepr(l)
         return '<%s%s %s>' % (_typename(self), d, s)
 
 class filteredset(abstractsmartset):
@@ -513,7 +513,7 @@
 
     @encoding.strmethod
     def __repr__(self):
-        xs = [pycompat.sysbytes(repr(self._subset))]
+        xs = [pycompat.byterepr(self._subset)]
         s = _formatsetrepr(self._condrepr)
         if s:
             xs.append(s)
@@ -1132,7 +1132,7 @@
 
 def prettyformat(revs):
     lines = []
-    rs = pycompat.sysbytes(repr(revs))
+    rs = pycompat.byterepr(revs)
     p = 0
     while p < len(rs):
         q = rs.find('<', p + 1)