--- a/mercurial/util.py	Thu Nov 21 15:46:35 2019 -0500
+++ b/mercurial/util.py	Fri Nov 22 21:42:04 2019 +0900
@@ -1906,7 +1906,7 @@
                         ) & 0x7FFFFFFF
                         os.utime(dest, (advanced, advanced))
         except shutil.Error as inst:
-            raise error.Abort(str(inst))
+            raise error.Abort(stringutil.forcebytestr(inst))
 
 
 def copyfiles(src, dst, hardlink=None, progress=None):