src/Pure/General/mercurial.scala

--- a/src/Pure/General/mercurial.scala	Sun May 16 13:14:16 2021 +0200
+++ b/src/Pure/General/mercurial.scala	Sun May 16 13:34:27 2021 +0200
@@ -376,7 +376,7 @@
 
           while (repos.importing) {
             progress.echo("Awaiting remote repository ...")
-            Time.seconds(0.5).sleep
+            Time.seconds(0.5).sleep()
             repos = phabricator.the_repository(repos.phid)
           }