remove uses of aliases

flake.nix

@@ -49,7 +49,7 @@
           components = defaultProfileComponents ++
             toolchainFile.toolchain.components;
           targets = toolchainFile.toolchain.targets;
-          fenix = inputs.fenix.packages.${pkgs.pkgsBuildHost.system};
+          fenix = inputs.fenix.packages.${pkgs.stdenv.buildPlatform.system};
         in
           fenix.combine (builtins.map
             (target:

nix/modules/default/default.nix

@@ -18,11 +18,11 @@ in
   options.services.grapevine = {
     enable = lib.mkEnableOption "grapevine";
     package = lib.mkPackageOption
-      inputs.self.packages.${pkgs.system}
+      inputs.self.packages.${pkgs.hostPlatform.system}
       "grapevine"
       {
         default = "default";
-        pkgsText = "inputs.grapevine.packages.\${pkgs.system}";
+        pkgsText = "inputs.grapevine.packages.\${pkgs.hostPlatform.system}";
       };
 
     settings = lib.mkOption {

nix/shell.nix

@@ -1,5 +1,6 @@
 # Keep sorted
-{ default
+{ buildPlatform
+, default
 , engage
 , inputs
 , jq
@@ -7,7 +8,6 @@
 , markdownlint-cli
 , mdbook
 , mkShell
-, system
 , toolchain
 }:
 
@@ -25,7 +25,7 @@ mkShell {
     #
     # This needs to come before `toolchain` in this list, otherwise
     # `$PATH` will have stable rustfmt instead.
-    inputs.fenix.packages.${system}.latest.rustfmt
+    inputs.fenix.packages.${buildPlatform.system}.latest.rustfmt
 
     # Keep sorted
     engage