At least as practiced at Google, a "blameless postmortem" doesn't mean nobody learns that something they did was partially responsible for an outage. But the focus is on finding out all the things that should have prevented the outage and fixing them. There's no point in blaming anyone, since they probably feel bad enough about it already.
For open source work: you file a bug. You don't call people names. The person who wrote the code is often consulted and may volunteer to fix it, but the focus is on fixing the bug, not blaming people.
At least as practiced at Google, a "blameless postmortem" doesn't mean nobody learns that something they did was partially responsible for an outage. But the focus is on finding out all the things that should have prevented the outage and fixing them. There's no point in blaming anyone, since they probably feel bad enough about it already.
For open source work: you file a bug. You don't call people names. The person who wrote the code is often consulted and may volunteer to fix it, but the focus is on fixing the bug, not blaming people.
[1] https://codeascraft.com/2012/05/22/blameless-postmortems/