Emacs overlay not working after updating

[codygman]

Update: related issue filed at #318

I'm not really sure what's going on here since I didn't change this piece. I use emacs overlay like this:

final: prev: {
  emacsGcc =
    let
      package = prev.emacsGcc.override ({ withXwidgets = true; });
      emacsPackages = prev.emacsPackagesNgGen package;
      emacsWithPackages = emacsPackages.emacsWithPackages;
    in
    emacsWithPackages (epkgs: with epkgs; [
      use-package
      magit
    ]);
}

It is tracked by the way:

devos2  try-upgrading-devos 「↪ 𝚫 ✔ 📁 」  ⎔ 
✦ ❯ git ls-files overlays/emacsGcc.nix 
overlays/emacsGcc.nix

It's not taking effect any more and seems to not apply to any pkgs such as those in my users/profiles/emacs/default.nix:

{ pkgs, ... }: {
  programs.emacs = {
    enable = true;
    package = pkgs.emacsGcc;
    # extraPackages = epkgs: [ epkgs.vterm epkgs.f ];
    extraPackages = import ./emacs-packages.nix;
  };

}

I think a while ago when I worked with @nrdxp over discord we had a similar issue where the order of overlays mattered for the emacs overlay.

So based on that hunch I'm about to try this in flake.nix:

digga.lib.mkFlake {
      inherit self inputs;

      channelsConfig = { allowUnfree = true; };

      channels = {
        nixos = {
          imports = [ (digga.lib.importers.overlays ./overlays) ];
          overlays = [
            ./pkgs/default.nix
+           emacs-overlay.overlay
            pkgs.overlay # for `srcs`
            nur.overlay
            agenix.overlay
-           emacs-overlay.overlay
          ];
        };
        latest = { };
      };

I have no idea if this will work, but the rationale is that maybe the pkg overlays have to happen after the emacs overlay is loaded.

Also, here is how I'm testing:

✦ ❯ emacs --batch --eval "(require 'magit)"
Debugger entered--Lisp error: (file-missing "Cannot open load file" "No such file or directory" "magit")
  require(magit)
  command-line-1(("--eval" "(require 'magit)"))
  command-line()
  normal-top-level()

Edit: Here is some extra context that could help:

✦ ❯ rg -C5 emacs-overlay -t nix
flake.nix
23-
24-      pkgs.url = "path:./pkgs";
25-      pkgs.inputs.nixpkgs.follows = "nixos";
26-
27-
28:      emacs-overlay.url = "github:nix-community/emacs-overlay";
29-    };
30-
31-  outputs =
32-    { self
33-    , pkgs
--
36-    , ci-agent
37-    , home
38-    , nixos-hardware
39-    , nur
40-    , agenix
41:    , emacs-overlay
42-    , ...
43-    } @ inputs:
44-    digga.lib.mkFlake {
45-      inherit self inputs;
46-
--
49-      channels = {
50-        nixos = {
51-          imports = [ (digga.lib.importers.overlays ./overlays) ];
52-          overlays = [
53-            ./pkgs/default.nix
54:            emacs-overlay.overlay
55-            pkgs.overlay # for `srcs`
56-            nur.overlay
57-            agenix.overlay
58-          ];
59-        };

devos2  try-upgrading-devos 「↪ ✘ 𝚫 ✔ 📁 」  ⎔ 
✦ ❯ rg emacsGcc -C5 -t nix
overlays/emacsGcc.nix
1-final: prev: {
2-
3:  emacsGcc =
4-    let
5:      package = prev.emacsGcc.override ({ withXwidgets = true; });
6-      emacsPackages = prev.emacsPackagesNgGen package;
7-      emacsWithPackages = emacsPackages.emacsWithPackages;
8-      app-launcher = emacsPackages.trivialBuild {
9-        pname = "app-launcher";
10-        src = prev.fetchurl {

users/profiles/emacs/default.nix
1-{ pkgs, ... }: {
2-  programs.emacs = {
3-    enable = true;
4:    package = pkgs.emacsGcc;
5-    # extraPackages = epkgs: [ epkgs.vterm epkgs.f ];
6-    extraPackages = import ./emacs-packages.nix;
7-  };
8-
9-#   home.file = {

devos2  try-upgrading-devos 「↪ ✘ 𝚫 ✔ 📁 」  ⎔ 
✦ ❯ rg profiles/emacs -C2 -t nix
users/cody/default.nix
28-
29-   home-manager.users.cody = {suites, ... }: {
30:    # imports = [ ../profiles/git ../profiles/direnv ../profiles/mail ../profiles/gpg ../profiles/emacs ];
31:    imports = suites.base ++ [ ../profiles/git ../profiles/direnv ../profiles/mail ../profiles/gpg ../profiles/emacs ];
32-
33-    # shouldn't this clash with environment.sessionVariables in develop/default.nix?

devos2  try-upgrading-devos 「↪ ✘ 𝚫 ✔ 📁 」  ⎔ 

[blaggacao]

Indeed the order of overlays matter. I strongly hypothesize that the raked overlays are applied first (via the module list merging mechanism).

This is an awkward behaviour since the raked overlays are usually meant to be applied post-external overlays.

I think this is in merit of a propper issue.

I remeber having stumbled over such thing, previously.

[blaggacao]

@codygman I edited your issue description so that we can quickly connect with the already somewhat "known" issue. Thanks for the report! 👍