See setup_publicinboxes() in lib/PublicInbox/TestCommon.pm.
-It is versioned (currently "1" in "home1") and will be renamed
-"home2" and so forth if the data created by setup_publicinboxes()
+It is versioned (currently "2" in "home2") and will be renamed
+"home3" and so forth if the data created by setup_publicinboxes()
changes.