Override postInstall for emacsOverlay

Help
1

I am using the GitHub - nix-community/emacs-overlay: Bleeding edge emacs overlay [maintainer=@adisbladis] which is already set up through flakes and want to override the postInstall script to add some bash at the end.

let doom-emacs = (pkgs.emacs).overrideAttrs (attrs: {
	postInstall = (attrs.postInstall or "") + ''
	mv ${inputs.doom-emacs} ${config.home.homeDirectory}/.emacs.d
	'';
});

but the service.emacs.package = pkgs.emacsGcc has no effect on the pkgs.emacs above, I have to change it to pkgs.emacsGcc directly instead. Also, for default pkgs.emacs, it starts to build the entire emacs where as normally it should be a binary and should not trigger a build. What is the correct way to override the Overlay?

2

The postInstall isn’t allowed to write in your $HOME.

What exactly are you trying to achieve?

3

I was trying to clone the doom emacs repo in .emacs.d along with emacs and run ~/.emacs.d/bin/doom install. Is there an actual way to do something like this or is my best bet just using nix-straight.el?

4

You can not do that in a derivation.

You need to either do the doom stuff manually or manage it through a nixos or home-manager module.

Though as I am not using doom myself, but vanilla emacs, I can’t tell you much more than that.

A quick web search though brought me to GitHub - vlaci/nix-doom-emacs: doom-emacs packaged for Nix, which seems to provide a wrapper that does doom fully in the store or a HM module to manage it thoruogh home.

5

Yes, nix-doom-emacs uses nix-straight.el. It completely manages doom-emacs where as I wanted to partially manage it (install doom-emacs and update it myself with ~/.emacs.d/bin/doom upgrade rather than through nix rebuild switch). This is because nix-straight.el gives much higher startup times than doing it manually myself. I just want to run

git clone --depth 1 https://github.com/hlissner/doom-emacs ~/.emacs.d
~/.emacs.d/bin/doom install -y

after installing emacs. I’m not sure if this is possible tho

6

You have to do that manually then.

In HM you could perhaps use activation scripts, though as they should be idempotent, its probably not a good idea to make them create folders without taking precautions.

7

I have previously looked into activation scripts. But I want to run this script exactly once (when I install emacs). A clever workaround would be to check if .emacs.d exists and write it if it doesn’t. Is there a way to run something like an activation script only once?

8

Nope, it will be run each time on activation, but of course you can wrap the script in a conditional.