--- a/contrib/import-checker.py	Wed Mar 02 10:14:24 2022 -0500
+++ b/contrib/import-checker.py	Wed Mar 02 10:23:53 2022 -0500
@@ -24,6 +24,7 @@
 allowsymbolimports = (
     '__future__',
     'breezy',
+    'concurrent',
     'hgclient',
     'mercurial',
     'mercurial.hgweb.common',