diff -r 818b4f19ef23 -r 4c1d39215034 mercurial/upgrade.py
--- a/mercurial/upgrade.py	Fri Jun 05 11:10:33 2020 -0700
+++ b/mercurial/upgrade.py	Wed May 27 12:26:08 2020 +0200
@@ -13,12 +13,12 @@
 from .pycompat import getattr
 from . import (
     changelog,
-    copies,
     error,
     filelog,
     hg,
     localrepo,
     manifest,
+    metadata,
     pycompat,
     revlog,
     scmutil,
@@ -734,9 +734,9 @@
             return False, (), {}
 
     elif localrepo.COPIESSDC_REQUIREMENT in addedreqs:
-        sidedatacompanion = copies.getsidedataadder(srcrepo, dstrepo)
+        sidedatacompanion = metadata.getsidedataadder(srcrepo, dstrepo)
     elif localrepo.COPIESSDC_REQUIREMENT in removedreqs:
-        sidedatacompanion = copies.getsidedataremover(srcrepo, dstrepo)
+        sidedatacompanion = metadata.getsidedataremover(srcrepo, dstrepo)
     return sidedatacompanion