Commit c89a33a07a 'debug: Use backends instead of explicitly logging to syslog or file' introduced a regression where early startup failures (e.g. unable to connect to CTDB) are no longer logged because the debug subsystem is not yet fully initialized. Samba 4.3 and higher is affected by this bug.
Created attachment 15092 [details] patches for 4.9
Created attachment 15093 [details] patches for 4.10
Pushed to autobuild-v4-{10,9}-test.
(In reply to Karolin Seeger from comment #3) Pushed to both branches. Closing out bug report. Thanks!