Long-standing ZFS bug involving encrypted datasets and send/rcv fixed!

A bug opened since May 2021, just a bit over 4 years ago, has finally been fixed: https://github.com/openzfs/zfs/issues/12014#issuecomment-2889132540

The fix itself is trivial, even though I am sure that finding the cause surely was not. But what really caught my attention was the CodeQL integration test that was written to prevent this issue from happening again.

I find CodeQL and similar tools (such as Opengrep/Semgrep) can be incredibly powerful in integration pipelines to prevent subtle, difficult to reproduce issues from happening again probably saving a lot of time in debugging and to write expensive integration tests.

I'd be curious to understand if CodeQL fares better in this context than Opengrep because it is aware of the code flow, as opposed to "just" matching patterns (I think Opengrep understands the code structure, to some extent but I'm not 100% sure). I do find CodeQL intimidating and more complex than Opengrep though: with the latter I was able to get something working in minutes, with CodeQL, took me hours just to read the docs and I was still confused as to how to write a check.

Anyways, I believe this will be an important skill for effective developers in the now and the future.

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