With this setup, you can use whatever local tool you want and, as long as environment variables are respected, they’ll just work. The only requirement on your end is to either run nix-shell first, or to use direnv and ask it to load the nix env for you.
The downside is you still are compiling locally, so you still need sufficient CPU/memory resources, but that’s it.
Unfortunately most companies still aren’t paying any attention to Nix.
Yes, the parent comment looks a bit complicated, but that's just the one time setup, not something that needs to be done by every developer. And Codespaces will require some of that setup too; it's not like it'll magically know what packages and dependancies your project requires to build.
If not, then it misses the main benefit outlined in the article.
But yes, once a project commits to using CodeSpaces dev environment (even and especially ones with large code / heavyweight environments) there is a lot that can be done to optimise the spawn up time, that cannot be done as easily for local dev.
That sounds incredibly useful actually. Is that the main sales pitch for codespaces?