Yeah makes sense, the workaround given is pretty ugly too. It does seem a little weird that nix run and nix shell -c do almost the same thing, where the latter is just more explicit.
I left a comment on a recent PR of my mine and I’d like to drop a quote from it since it seems relavent to the overall point of this thread:
we may want to consider a more “plumbing” and “porceline” approach for flakes 2.0, to keep drift between the old and new commands from becoming a big issue.
I like the low-level control the legacy commands give me when I need that. Say in a complex CI system that focuses on doing as little work as possible, but I like the higher level commands for ease of use when working on my own system. I think there is an argument to be made for keeping both around and taking implementations from the lower-level commands and reusing them for their flake counterparts.
Perhaps I am missing something, but a more “git-like” approach may be the key to refining the UX in the future without sacrificing power where required.