Evaluating attribute `exe` on `project ./. {...}` require more than 4.5 GiB free space

[TheKK]

There are some issues relate to this.

First, this make CI difficult to run. Some CI environment, like GitHub action, doesn't allow a single job to use so much space so it would fail unless we have certain cache first. I saw package like newtype-0.2.1.0-js-unknown-ghcjs-doc which might not be needed while evaluating exe.

The second issue is that we need some better way to debug and cache derivations used by IFD (import from derivation). At least I didn't see any documentation talks about these kinds of techniques.

[madeline-os]

Hi, I apologize for the long delay on responding to this ticket. You are right that the amount of space required to evaluate is unreasonable, and difficult to cache. IFD is tricky to wrangle right now because of a lack of upstream tooling. Some hope on the horizon: https://github.com/NixOS/nix/pull/3494 If improvements to nix like this can be merged, we will be able to address this issue directly.

IFD is a little bit neglected as a feature because of its complexity. Of course, obelisk uses a great deal of IFD. It helps all of us when people voice their concerns with the nix maintainers so that they understand that there is a demand for investment into IFD, so I encourage you to chime in upstream.