My setup, with initial keymap

flake.nix

@@ -0,0 +1,50 @@
+{
+  outputs = {
+    self,
+    nixpkgs,
+  }: let
+    sys = "x86_64-linux";
+    pkgs = nixpkgs.legacyPackages.${sys};
+  in {
+    packages.${sys} = rec {
+      python3 = pkgs.python3.override {
+        packageOverrides = final: prev: {
+          milc = prev.milc.overrideAttrs {
+            patches = [
+              # Logs pre-initialization give long exceptions without this - they try to write directly to str('/dev/null')
+              # This effects every `qmk` command post-userspaces, as they have an import-time 'find the userspace' operation
+              # that logs in several different substeps
+              # I have *no* idea how noone else has run into this at all, but I can't find any mention of it as an issue anywhere
+              (pkgs.writeText "patch" ''
+                diff --git a/milc/__init__.py b/milc/__init__.py
+                index b3e7158..4f2843e 100644
+                --- a/milc/__init__.py
+                +++ b/milc/__init__.py
+                @@ -39,7 +39,7 @@ if 'MILC_IGNORE_DEPRECATED' not in os.environ:
+                         if name in os.environ:
+                             warnings.warn(f'Using {name} is deprecated and will not be supported in the future, please use set_metadata() instead.', stacklevel=2)
+
+                -logging.basicConfig(stream=os.devnull)  # Disable logging until we can configure it how the user wants
+                +logging.basicConfig(filename=os.devnull)  # Disable logging until we can configure it how the user wants
+
+                 cli = MILC(APP_NAME, APP_VERSION, APP_AUTHOR)
+              '')
+            ];
+          };
+        };
+      };
+
+      qmk = pkgs.qmk.override {inherit python3;};
+    };
+    devShells.${sys}.default = pkgs.mkShell {
+      packages = with pkgs; [
+        self.packages.${sys}.qmk
+        clang
+        clang-tools
+      ];
+      shellHook = ''
+        export QMK_HOME=$PWD/qmk_firmware
+      '';
+    };
+  };
+}