diff --git a/flake.nix b/flake.nix
index ee7135b..9b13ad6 100644
--- a/flake.nix
+++ b/flake.nix
@@ -44,158 +44,105 @@
 
         pkgs = import nixpkgs { inherit overlays system; };
         craneLib = (crane.mkLib pkgs).overrideToolchain pkgs.rust-toolchain;
-        stdenv = pkgs.stdenvAdapters.useMoldLinker pkgs.stdenv;
 
-        nativeBuildInputs = with pkgs; [
-          clang_18
-          mold
-          pkg-config
-        ];
-
-        jsonFilter = path: _type: builtins.match ".*json$" path != null;
-        sourceAndFixtures = path: type:
-          (jsonFilter path type) || (craneLib.filterCargoSources path type);
-        src = pkgs.lib.cleanSourceWith {
-          src = ./.;
-          filter = sourceAndFixtures;
+        src = pkgs.lib.fileset.toSource {
+          root = ./.;
+          fileset = pkgs.lib.fileset.unions [
+            ./api.json
+            (craneLib.fileset.commonCargoSources ./.)
+          ];
         };
 
         commonArgs = {
-          inherit src stdenv nativeBuildInputs;
+          inherit src;
+
+          stdenv = pkgs.stdenvAdapters.useMoldLinker pkgs.stdenv;
           strictDeps = true;
-          LIBCLANG_PATH = "${pkgs.llvmPackages.libclang.lib}/lib";
+          cargoArtifacts = craneLib.buildDepsOnly commonArgs;
+
+          nativeBuildInputs = with pkgs; [
+            clang
+            mold-wrapped
+            pkg-config
+          ];
+
           buildInputs = with pkgs; [
             openssl
           ];
         };
 
-        cargoArtifacts = craneLib.buildDepsOnly commonArgs;
-
-        individualCrateArgs = commonArgs // {
-          inherit cargoArtifacts;
-          inherit (craneLib.crateNameFromCargoToml { inherit src; }) version;
-          doCheck = false; # We use cargo-nextest for all tests
-        };
-
-        fileSetForCrate =
-          crate:
-          pkgs.lib.fileset.toSource {
-            root = ./.;
-            fileset = pkgs.lib.fileset.unions [
-              ./api.json
-              ./Cargo.toml
-              ./Cargo.lock
-              (craneLib.fileset.commonCargoSources ./agent)
-              (craneLib.fileset.commonCargoSources ./controller)
-              (craneLib.fileset.commonCargoSources ./xtask)
-              (craneLib.fileset.commonCargoSources crate)
-            ];
+        buildCrate =
+          name: path:
+          craneLib.buildPackage commonArgs
+          // {
+            inherit (craneLib.crateNameFromCargoToml { inherit src; }) version;
+            doCheck = false; # We use cargo-nextest for all tests
+            pname = name;
+            cargoExtraArgs = "-p ${name}";
           };
 
-        patagia-agent = craneLib.buildPackage (
-          individualCrateArgs
-          // {
-            pname = "patagia-agent";
-            cargoExtraArgs = "-p patagia-agent";
-            src = fileSetForCrate ./agent;
-          }
-        );
-
-        patagia-controller = craneLib.buildPackage (
-          individualCrateArgs
-          // {
-            pname = "patagia-controller";
-            cargoExtraArgs = "-p patagia-controller";
-            src = fileSetForCrate ./controller;
-          }
-        );
-
-        xtask = craneLib.buildPackage (
-          individualCrateArgs
-          // {
-            pname = "xtask";
-            cargoExtraArgs = "-p xtask";
-            src = fileSetForCrate ./xtask;
-          }
-        );
-
-        treefmtEval = treefmt-nix.lib.evalModule pkgs {
-          projectRootFile = "flake.nix";
-          programs = {
-            nixfmt.enable = true;
-            nixfmt.package = pkgs.nixfmt-rfc-style;
-            shfmt.enable = true;
-            rustfmt.enable = true;
-          };
-          settings.formatter.rustfmt.command = pkgs.lib.mkForce "${pkgs.rust-toolchain}/bin/rustfmt";
-        };
-
+        patagia-agent = buildCrate "patagia-agent" ./agent;
+        patagia-controller = buildCrate "patagia-controller" ./controller;
+        xtask = buildCrate "xtask" ./xtask;
       in
       {
-        # `nix build`
         packages = {
           inherit patagia-agent patagia-controller xtask;
         };
 
-        # Tests
         checks = {
           inherit patagia-agent patagia-controller xtask;
 
-          clippy = craneLib.cargoClippy (
-            commonArgs
-            // {
-              inherit cargoArtifacts;
-              cargoClippyExtraArgs = "--all-targets -- --deny warnings";
-            }
-          );
+          audit = craneLib.cargoAudit (commonArgs // { inherit advisory-db; });
 
-          # fmt = craneLib.cargoFmt (commonArgs // { inherit src; });
+          clippy = craneLib.cargoClippy commonArgs // {
+            cargoClippyExtraArgs = "--all-targets -- --deny warnings";
+          };
 
-          audit = craneLib.cargoAudit (commonArgs // { inherit src advisory-db; });
+          fmt = craneLib.cargoFmt commonArgs;
 
-          nextest = craneLib.cargoNextest (
-            commonArgs
-            // {
-              inherit cargoArtifacts;
-              partitions = 1;
-              partitionType = "count";
-            }
-          );
+          nextest = craneLib.cargoNextest commonArgs // {
+            partitions = 1;
+            partitionType = "count";
+          };
 
-          openapi =
-            pkgs.runCommand "openapi"
-              (
-                commonArgs
-                // {
-                  inherit cargoArtifacts;
-                  src = fileSetForCrate ./xtask;
-                }
-              )
-              ''
-                ${self.packages.${system}.xtask}/bin/xtask open-api | ${pkgs.diffutils}/bin/diff -u $src/api.json - | tee $out
-              '';
+          openapi = pkgs.runCommand "openapi" commonArgs ''
+            ${self.packages.${system}.xtask}/bin/xtask open-api |
+              ${pkgs.diffutils}/bin/diff -u $src/api.json - |
+              tee $out
+          '';
         };
 
-        # For `nix fmt`
-        formatter = treefmtEval.config.build.wrapper;
+        formatter =
+          (treefmt-nix.lib.evalModule pkgs {
+            projectRootFile = "flake.nix";
+            programs = {
+              nixfmt.enable = true;
+              nixfmt.package = pkgs.nixfmt-rfc-style;
+              shfmt.enable = true;
+              rustfmt.enable = true;
+            };
+            settings.formatter.rustfmt.command = pkgs.lib.mkForce "${pkgs.rust-toolchain}/bin/rustfmt";
+          }).config.build.wrapper;
 
-        # `nix develop`
         devShells.default = pkgs.mkShell {
-          inherit nativeBuildInputs;
-          buildInputs = with pkgs; [
-            bacon
-            cargo-edit
-            cargo-features-manager
-            cargo-hakari
-            cargo-machete
-            cargo-nextest
-            cargo-watch
-            hyperfine
-            openssl
-            just
-            rust-dev-toolchain
-            watchexec
-          ];
+          nativeBuildInputs = commonArgs.nativeBuildInputs;
+          buildInputs =
+            with pkgs;
+            [
+              bacon
+              cargo-edit
+              cargo-features-manager
+              cargo-hakari
+              cargo-machete
+              cargo-nextest
+              cargo-watch
+              hyperfine
+              just
+              rust-dev-toolchain
+              watchexec
+            ]
+            ++ commonArgs.buildInputs;
           RUST_BACKTRACE = 1;
           RUST_SRC_PATH = pkgs.rustPlatform.rustLibSrc; # Required for rust-analyzer
           shellHook = ''