overlays: break apart overlays

nix/configurations/vanadium.nix

@@ -37,16 +37,18 @@ in
           };
 
           hostPlatform = system;
-          overlays = with (import ../overlays); [
-            agenix
-            disko
-            nur
-            wired-notify
-            emacs28 # removed, but I need it for PLFA!
-            nix-tree
+          overlays = map import [
+            ../overlays/agenix.nix
+            ../overlays/disko.nix
+            ../overlays/nur.nix
+            ../overlays/wired-notify.nix
+            ../overlays/nix-tree.nix
 
-            packages
-            (import ./vanadium/nixos/overlay.nix)
+            ../overlays/packages.nix
+            ./vanadium/nixos/overlay.nix
+
+            # removed, but I need it for PLFA!
+            ../overlays/pin-emacs28.nix
           ];
 
           # Set NIX_PATH and flake registry at the same time

nix/overlays/agenix.nix

@@ -1,6 +1,6 @@
 let
-  sources = import ../../../sources.nix;
+  sources = import ../sources.nix;
 in
-  final: prev: {
+  final: _: {
     inherit (final.callPackage sources.agenix {}) agenix;
   }

nix/overlays/by-name.nix

@@ -1,12 +0,0 @@
-let
-  sources = import ../sources.nix;
-  lib = import (sources.nixpkgs + "/lib");
-in
-  lib.mapAttrs
-  (
-    name: _:
-      import (./by-name + "/${name}/overlay.nix")
-  )
-  (
-    lib.filterAttrs (_: type: type == "directory") (builtins.readDir ./by-name)
-  )

nix/overlays/by-name/emacs28/overlay.nix

@@ -1,9 +0,0 @@
-let
-  sources = import ../../../sources.nix;
-in
-  _: _: {
-    emacs28 = let
-      pkgs = import sources.pin-emacs28 {};
-    in
-      pkgs.emacs;
-  }

nix/overlays/default.nix

@@ -1,2 +0,0 @@
-import ./by-name.nix
-// {packages = import ./packages.nix;}

nix/overlays/disko.nix

@@ -1,5 +1,5 @@
 let
-  sources = import ../../../sources.nix;
+  sources = import ../sources.nix;
 in
   final: _: {
     disko =

nix/overlays/nix-tree.nix

@@ -1,7 +1,7 @@
 # The one in nixpkgs doesn't work
 # Getting nix-tree: user error (Failed parsing nix path-info output.)
 let
-  sources = import ../../../sources.nix;
+  sources = import ../sources.nix;
 in
   final: _: {
     nix-tree = (import sources.nix-tree).packages.${final.system}.default;

nix/overlays/nur.nix

@@ -1,5 +1,5 @@
 let
-  sources = import ../../../sources.nix;
+  sources = import ../sources.nix;
 in
   _: prev: {
     nur = import sources.nur {

nix/overlays/pin-emacs28.nix

@@ -0,0 +1,6 @@
+let
+  sources = import ../sources.nix;
+in
+  _: _: {
+    emacs28 = (import sources.pin-emacs28 {}).emacs;
+  }

nix/overlays/pin-isabelle-2023.nix

@@ -1,5 +1,5 @@
 let
-  sources = import ../../../sources.nix;
+  sources = import ../sources.nix;
 in
   _: _: {
     # Isabelle version 2023

nix/overlays/pin-wireshark.nix

@@ -1,5 +1,5 @@
 let
-  sources = import ../../../sources.nix;
+  sources = import ../sources.nix;
 in
   _: _: {
     # Wireshark bug

nix/overlays/wired-notify.nix

@@ -1,4 +1,4 @@
 let
-  sources = import ../../../sources.nix;
+  sources = import ../sources.nix;
 in
   (import sources.wired-notify).overlays.default