Refactor flake.nix slightly

build.rs

@@ -1,5 +1,5 @@
 fn main() {
-    println!("cargo:rustc-link-search=native=lib");
+    println!("cargo:rustc-link-search=native={}", env!("SITTERS"));
     for lang in &[
         #[cfg(feature = "bash")]
         "bash",

flake.nix

@@ -9,7 +9,9 @@
 
   outputs = { self, nixpkgs, flake-utils, rust-overlay, tree-sitters }:
     flake-utils.lib.eachDefaultSystem (sys:
-      let pkgs = import nixpkgs {
+      let enabledSitters = ["bash" "c" "python" "rust" "nix" "agda" "html" "javascript"];
+
+          pkgs = import nixpkgs {
             system = sys;
             overlays = [ (import rust-overlay) ];
           };
@@ -20,25 +22,25 @@
             rustc = rust;
             cargo = rust;
           };
-          sitters = tree-sitters.packages.${sys};
-          sitterlist = [
-            sitters.bash sitters.c sitters.python sitters.rust sitters.nix sitters.agda sitters.html sitters.javascript
-          ];
+
+          sitterlist = map (lang: tree-sitters.packages.${sys}.${lang}) enabledSitters;
+
+          sitters = pkgs.runCommand "sitters" {inherit sitterlist;} ''
+            mkdir -p $out
+            for sitter in $sitterlist ; do
+              echo "Copying $sitter"
+              cp $sitter/lib/*.a $out
+            done
+          '';
 
           kak-tree-bin = platform.buildRustPackage {
             name = "kak-tree-bin";
             src = ./.;
             cargoLock = { lockFile = ./Cargo.lock; };
-            buildFeatures = ["bash" "c" "python" "rust" "nix" "agda" "html" "javascript"];
-            inherit sitterlist;
-            preBuild = ''
-              mkdir lib
-              for sitter in $sitterlist ; do
-                echo "Copying $sitter"
-                cp $sitter/lib/* lib
-              done
-            '';
+            buildFeatures = enabledSitters;
             doCheck = false;
+
+            SITTERS = sitters;
           };
 
       in rec {
@@ -58,6 +60,9 @@
         };
         devShells.default = pkgs.mkShell {
           packages = [ rust ];
+          shellHook = ''
+            export SITTERS="${sitters}"
+          '';
         };
       }
     );