ema VS haskell-template

You can baptize yourself by either moving a sufficiently complex Haskell codebase to Nix or building a website using something like Ema (with full Nix+Flakes support!)

Also, I'm willing to mentor anyone who is interested in improving Ema or Emanote.

Clarification: Emanote is a successor to Neuron, and written on top of Ema.

I maintain an extended version of Emanote in Haskell (as an Ema app) that does custom stuff like visualize my hledger transactions, track time, generate invoice and provide custom views of my Markdown notebook, like a Twitter-like timeline generated from H2 headings (with date) from across notes.

I am a Haskell newbie myself. Found nix flakes and https://github.com/srid/haskell-template really nice to start with (of course some learning curve is unavoidable).

If you wanna get started with Haskell on Nix, check out Sridhar Ratnakumar's Haskell template for Nix. You can easily clone the repo and move your Haskell code into it, especially if you're still a novice (as you likely won't be dealing with a HUGE codebase).

I'd say that's up to you. haskell-template did recently switch to this; you can see the changes in this PR, which is all limited to flake.nix.

Could you open an issue here with the full error message?

I think you should use ghcup because Nix has a higher learning curve ... BUT if you ever want to try out Nix, there is https://github.com/srid/haskell-template which sets everything up for you so that things "just work" in VSCode.