@isabel next time you go in a merging spree, I have this one waiting for a while if you're interested:
https://github.com/NixOS/nixpkgs/pull/494240

dasel: 2.8.1 -> 3.3.0 by just1602 · Pull Request #494240 · NixOS/nixpkgs
This is a major version bump with breaking changes.
The interface changed a lot, so I fixed the installCheckPhase script.
I removed shell completions since they have been dropped upstream, there...
GitHub