diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000000..536c8259b1
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,25 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1690630721,
+        "narHash": "sha256-Y04onHyBQT4Erfr2fc82dbJTfXGYrf4V0ysLUYnPOP8=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "d2b52322f35597c62abf56de91b0236746b2a03d",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000000..1f35c02c6e
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,81 @@
+# Important note: this flake does not attempt to create a fully isolated, 'pure'
+# Python environment for InvokeAI. Instead, it depends on local invocations of
+# virtualenv/pip to install the required (binary) packages, most importantly the
+# prebuilt binary pytorch packages with CUDA support.
+# ML Python packages with CUDA support, like pytorch, are notoriously expensive
+# to compile so it's purposefuly not what this flake does.
+
+{
+  description = "An (impure) flake to develop on InvokeAI.";
+
+  outputs = { self, nixpkgs }:
+    let
+      system = "x86_64-linux";
+      pkgs = import nixpkgs {
+        inherit system;
+        config.allowUnfree = true;
+      };
+
+      python = pkgs.python310;
+
+      mkShell = { dir, install }:
+        let
+          setupScript = pkgs.writeScript "setup-invokai" ''
+            # This must be sourced using 'source', not executed.
+            ${python}/bin/python -m venv ${dir}
+            ${dir}/bin/python -m pip install ${install}
+            # ${dir}/bin/python -c 'import torch; assert(torch.cuda.is_available())'
+            source ${dir}/bin/activate
+          '';
+        in
+        pkgs.mkShell rec {
+          buildInputs = with pkgs; [
+            # Backend: graphics, CUDA.
+            cudaPackages.cudnn
+            cudaPackages.cuda_nvrtc
+            cudatoolkit
+            freeglut
+            glib
+            gperf
+            procps
+            libGL
+            libGLU
+            linuxPackages.nvidia_x11
+            python
+            stdenv.cc
+            stdenv.cc.cc.lib
+            xorg.libX11
+            xorg.libXext
+            xorg.libXi
+            xorg.libXmu
+            xorg.libXrandr
+            xorg.libXv
+            zlib
+
+            # Pre-commit hooks.
+            black
+
+            # Frontend.
+            yarn
+            nodejs
+          ];
+          LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath buildInputs;
+          CUDA_PATH = pkgs.cudatoolkit;
+          EXTRA_LDFLAGS = "-L${pkgs.linuxPackages.nvidia_x11}/lib";
+          shellHook = ''
+            if [[ -f "${dir}/bin/activate" ]]; then
+              source "${dir}/bin/activate"
+              echo "Using Python: $(which python)"
+            else
+              echo "Use 'source ${setupScript}' to set up the environment."
+            fi
+          '';
+        };
+    in
+    {
+      devShells.${system} = rec {
+        develop = mkShell { dir = "venv"; install = "-e '.[xformers]' --extra-index-url https://download.pytorch.org/whl/cu118"; };
+        default = develop;
+      };
+    };
+}
diff --git a/invokeai/app/services/config.py b/invokeai/app/services/config.py
index a3508e11ba..a9a4a64f75 100644
--- a/invokeai/app/services/config.py
+++ b/invokeai/app/services/config.py
@@ -274,7 +274,7 @@ class InvokeAISettings(BaseSettings):
     @classmethod
     def _excluded(self) -> List[str]:
         # internal fields that shouldn't be exposed as command line options
-        return ["type", "initconf"]
+        return ["type", "initconf", "cached_root"]
 
     @classmethod
     def _excluded_from_yaml(self) -> List[str]:
@@ -290,6 +290,7 @@ class InvokeAISettings(BaseSettings):
             "restore",
             "root",
             "nsfw_checker",
+            "cached_root",
         ]
 
     class Config:
@@ -423,6 +424,7 @@ class InvokeAIAppConfig(InvokeAISettings):
     log_level           : Literal[tuple(["debug","info","warning","error","critical"])] = Field(default="info", description="Emit logging messages at this level or  higher", category="Logging")
 
     version             : bool = Field(default=False, description="Show InvokeAI version and exit", category="Other")
+    cached_root         : Path = Field(default=None,  description="internal use only", category="DEPRECATED")
     # fmt: on
 
     def parse_args(self, argv: List[str] = None, conf: DictConfig = None, clobber=False):
@@ -470,10 +472,15 @@ class InvokeAIAppConfig(InvokeAISettings):
         """
         Path to the runtime root directory
         """
-        if self.root:
-            return Path(self.root).expanduser().absolute()
+        # we cache value of root to protect against it being '.' and the cwd changing
+        if self.cached_root:
+            root = self.cached_root
+        elif self.root:
+            root = Path(self.root).expanduser().absolute()
         else:
-            return self.find_root()
+            root = self.find_root()
+        self.cached_root = root
+        return self.cached_root
 
     @property
     def root_dir(self) -> Path:
diff --git a/invokeai/frontend/merge/merge_diffusers.py b/invokeai/frontend/merge/merge_diffusers.py
index 81a7b3f6c8..db493ec17f 100644
--- a/invokeai/frontend/merge/merge_diffusers.py
+++ b/invokeai/frontend/merge/merge_diffusers.py
@@ -320,7 +320,7 @@ class mergeModelsForm(npyscreen.FormMultiPageAction):
 
     def get_model_names(self, base_model: BaseModelType = None) -> List[str]:
         model_names = [
-            info["name"]
+            info["model_name"]
             for info in self.model_manager.list_models(model_type=ModelType.Main, base_model=base_model)
             if info["model_format"] == "diffusers"
         ]