flake: add ${projname} var instead of a literal

flake.nix

@@ -19,6 +19,8 @@
   outputs = { self, nixgl, nix-filter, nixpkgs, ... }:
     let
 
+      projname = "go-xkcdreader";
+
       # to work with older version of flakes
       lastModifiedDate =
         self.lastModifiedDate or self.lastModified or "19700101";
@@ -54,7 +56,7 @@
         in
         rec {
           go-xkcdreader = with pkgs; buildGoModule rec {
-            pname = "go-xkcdreader";
+            pname = "${projname}";
             buildInputs = [
               gcc
               libglvnd # instead of libGL
@@ -107,7 +109,7 @@
 
             meta = {
               description = "an offline-capable xkcd webcomic reader written in Go";
-              homepage = "https://git.dotya.ml/wanderer/go-xkcdreader";
+              homepage = "https://git.dotya.ml/wanderer/${projname}";
               license = lib.licenses.gpl3;
               maintainers = [ "wanderer" ];
               platforms = lib.platforms.linux ++ lib.platforms.darwin;
@@ -121,7 +123,7 @@
         go-xkcdreader = {
           type = "app";
           program =
-            "${self.packages.${system}.go-xkcdreader}/bin/go-xkcdreader";
+            "${self.packages.${system}.${projname}}/bin/${projname}";
         };
         default = go-xkcdreader;
       });
@@ -154,7 +156,7 @@
             nix-store --query --references $(nix-instantiate shell.nix) | \
               xargs nix-store --realise | \
               xargs nix-store --query --requisites | \
-              cachix push go-xkcdreader
+              cachix push ${projname}
           '';
           add-license = pkgs.writeShellScriptBin "add-license" ''
             go run github.com/google/addlicense@v1.0.0 -v \
@@ -165,7 +167,7 @@
         {
           default = with pkgs; mkShell
             {
-              name = "go-xkcdreader-" + version;
+              name = "${projname}-" + version;
 
               GOFLAGS = "-buildmode=pie -trimpath -mod=readonly -modcacherw";
               GOLDFLAGS = "-s -w -X cmd.version=${version}";