Reuse nixpkgs recipe as suggested by @tirimia

default.nix

@@ -1,37 +0,0 @@
-{ pkgs }:
-let
-  version =
-    let
-      cargoToml = builtins.readFile ./Cargo.toml;
-      match = builtins.match ''.*version = "([^"]+)".*'' cargoToml;
-    in
-    if match != null then builtins.elemAt match 0 else throw "Version not found in Cargo.toml";
-in
-{
-  app = pkgs.rustPlatform.buildRustPackage {
-    pname = "lychee";
-    inherit version;
-    src = ./.;
-
-    cargoLock = {
-      lockFile = ./Cargo.lock;
-    };
-
-    nativeBuildInputs = [ pkgs.pkg-config ];
-    buildInputs =
-      [ pkgs.openssl ]
-      ++ pkgs.lib.optionals pkgs.stdenv.hostPlatform.isDarwin [
-        pkgs.Security
-        pkgs.SystemConfiguration
-      ];
-
-    PKG_CONFIG_PATH = "${pkgs.openssl.dev}/lib/pkgconfig";
-    RUST_BACKTRACE = 1;
-
-    checkFlags = [
-      "--skip=src/lib.rs"
-      "--skip=client::tests"
-      "--skip=collector::tests::test_url_without_extension_is_html"
-    ];
-  };
-}

flake.nix

@@ -9,6 +9,7 @@
     {
       nixpkgs,
       rust-overlay,
+      self,
       ...
     }:
     let
@@ -51,10 +52,15 @@
         system:
         let
           pkgs = nixpkgs.legacyPackages.${system};
-          code = import ./default.nix { inherit pkgs; };
         in
         {
-          default = code.app;
+          default = pkgs.lychee.overrideAttrs {
+            src = ./.;
+            version = self.rev or self.dirtyShortRev;
+            cargoDeps = pkgs.rustPlatform.importCargoLock {
+              lockFile = ./Cargo.lock;
+            };
+          };
         }
       );
     };