Comment #17 in particular suggests "private/tlsmgr" is probably a red herring, and comment #21 and #23 have some good debugging analysis. Comments #26 and subsequent focus on fixing dane support due to breakage by glibc, released as 3.4.13-0ubuntu1. Comments #43 and #44 are splitting the remaining issue with posttls-finger out as this bug report.
Aha, bunch more analysis was done on this issue as part of this:
https:/ /bugs.launchpad .net/ubuntu/ +source/ postfix/ +bug/1868955
Comment #17 in particular suggests "private/tlsmgr" is probably a red herring, and comment #21 and #23 have some good debugging analysis. Comments #26 and subsequent focus on fixing dane support due to breakage by glibc, released as 3.4.13-0ubuntu1. Comments #43 and #44 are splitting the remaining issue with posttls-finger out as this bug report.