diff --git a/flake.nix b/flake.nix
index 3bfb136..c5f42c7 100644
--- a/flake.nix
+++ b/flake.nix
@@ -23,7 +23,8 @@
           };
 
           devShells = {
-            aby = import ./nix/zig.nix { pkgs = pkgs; };
+            aby = import ./nix/aby.nix { pkgs = pkgs; };
+            empty = import ./nix/empty.nix { pkgs = pkgs; };
             zig = import ./nix/zig.nix { pkgs = pkgs; };
           };
         }) // {
diff --git a/nix/aby.nix b/nix/aby.nix
index 5ce744c..3649d56 100644
--- a/nix/aby.nix
+++ b/nix/aby.nix
@@ -1,4 +1,4 @@
-{ pkgs ? import <nixpkgs> {} }:
+{ pkgs }:
 
 pkgs.mkShell {
   buildInputs = with pkgs; [
@@ -8,6 +8,6 @@ pkgs.mkShell {
     openssl
     doxygen
     ninja
-    llvmPackages_12.clang
+    llvmPackages_13.clang
   ];
 }
diff --git a/nix/empty.nix b/nix/empty.nix
new file mode 100644
index 0000000..40d3e99
--- /dev/null
+++ b/nix/empty.nix
@@ -0,0 +1,6 @@
+{ pkgs }:
+
+pkgs.mkShell {
+  buildInputs = with pkgs; [
+  ];
+}
diff --git a/nix/laplace.nix b/nix/laplace.nix
index 2aa9557..f4e7352 100644
--- a/nix/laplace.nix
+++ b/nix/laplace.nix
@@ -1,4 +1,4 @@
-{ pkgs ? import <nixpkgs> {} }:
+{ pkgs ? import <nixpkgs> { } }:
 with pkgs;
 
 buildGoModule rec {
@@ -12,5 +12,5 @@ buildGoModule rec {
     sha256 = "0l7w7my64yi2pig8sdxgk8049ah3n1mb2wfw858ys3gk42xqa5xh";
   };
 
- vendorSha256 = "022bil46fyjsd18diw0rnab987sp1ialb48rj18ksj75ghjqkr62";
+  vendorSha256 = "022bil46fyjsd18diw0rnab987sp1ialb48rj18ksj75ghjqkr62";
 }
diff --git a/nix/motion.nix b/nix/motion.nix
index 1c403ba..dd04e32 100644
--- a/nix/motion.nix
+++ b/nix/motion.nix
@@ -1,4 +1,4 @@
-{ pkgs ? import <nixpkgs> {} }:
+{ pkgs ? import <nixpkgs> { } }:
 
 pkgs.mkShell {
   buildInputs = with pkgs; [
diff --git a/nix/river.nix b/nix/river.nix
index 4182a80..1980b2f 100644
--- a/nix/river.nix
+++ b/nix/river.nix
@@ -1,4 +1,4 @@
-{ pkgs ? import <nixpkgs> {} }:
+{ pkgs ? import <nixpkgs> { } }:
 
 pkgs.stdenv.mkDerivation rec {
   pname = "river";