#868 (Feb 16, 2019, 12:50:08 AM)

1. clarified meta_digest: export_files is a directive for physical output from existing build database; (detail / hgweb)
2. clarified 'export_files' in session ROOT: require explicit "isabelle build -e";
   tuned messages; (detail / hgweb)
3. clarified name; (detail / hgweb)

Started by an SCM change

This run spent:

• 6.8 sec waiting;
• 1 hr 18 min build duration;
• 1 hr 18 min total from scheduled to completion.