As someone who sometimes uses Nix to put together devShells for small projects at work, I admit there are times I might be inclined to point someone to the flak

As someone who sometimes uses Nix to put together devShells for small projects at work, I admit there are times I might be inclined to point someone to the flake as a workaround for a versioning issue. But I would still consider it a bug in my app to be broken with a newer version of a library than what I have pinned. I believe many developers must feel similarly! At the end of the day, when it comes to development environments, Nix should be a way to help provide a reproducible fast track for building and/or running the software, not a preemptive dismissal of all other possible downstream users and distros! If your software has a Nix flake but no build instructions, it's missing documentation. That's probably okay for solo open-source projects that are small and indifferent to building a userbase, but I hope maintainers and companies will readily recognize that as they grow they'll have to fill that gap at some point.