WDYM by "directory it drops down into"? nix develop stays in your current working directory.
If I wanted to clean up state, I'd create a clean task in the build system or build a clean script that I'd wire up to the flake outputs such that you could run nix run .#clean.
I see, thanks
As for "drop down", I was loosely referring to the newly spawned terminal
clean scripts get the job done. I was thinking of persisting changes to the filesystem state only while the ephemeral shell was live, that way every time I ran nix develop i would check to make sure my project could automatically build, and If there was any state that needed persisting, I would have to commit/push and label those changes somewhere before ending my session
You could achieve something like that using bubblewrap; effectively a container. You can tell it to mount tmpfs wherever you like. That has other issues though.
That's a big of a complex setup which other people potentially working with you may not want to have. A clean task is just better. If you're using git anyways, you can also just use git clean.
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