It would be great if there was a recommended formatting tool and config file for the nix project. Working on the last nix-errors PR I spent a few days trying to find a tool that would match the existing formatting, but I wasn't able to get anything to work perfectly. That PR was already huge, so a bunch of noise from reformatting would not have helped matters.

I tried astyle, uncrustify, and clang-format. Uncrustify was probably closest - its has a ton of configuration options. Astyle was also decent, arguably because it mostly leaves the code alone compared to the others. clang-format was in third place for me, but perhaps it could have been made to work by spending more time on it. I didn't save my config attempts with that one.

Here's where I left off with uncrustify:
uncrustify.cfg.txt

And here's a diff with the default uncrustify settings:
uncrustify.diff.txt

Unfortunately I don't appear to have saved my astyle settings, but its way less involved than the above. I'd like to hear if anyone has had more luck than me with formatting!