imports: allow importing futures from concurrent
Differential Revision: https://phab.mercurial-scm.org/D12278
--- 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',