Introduce pyproject-nix overlay in nix flake (#4862)

In the past, when we were using poetry2nix, we used additional overlays
in nix to ensure that nix flake overrides, e.g. `nix build
--override-input kevm/k-framework v1.0.0`, do not only override the nix
flake but also the python package that was locked in `poetry.lock`.

With the migration to `uv2nix`, this overlay was removed, causing
confusion and overhead when wanting to override python code using nix
flake overrides. This PR re-introduces these overlays that can be used
in dependent nix flakes to re-establish this behaviour. Due to `uv2nix`
using the newer nix python packaging tooling `pyproject-nix`, this code
adds more complexity in comparison to `poetry2nix`, though it
nonetheless achieves the same result.

There will be similar PRs in other repositories introducing and using
these pyproject-nix overlays.

Author: juliankuners

flake.nix

@@ -39,12 +39,16 @@
         uv = uv2nix.packages.${final.system}.uv-bin;
       };
       pykOverlay = final: prev: rec {
+        pyk-pyproject = final.callPackage ./nix/pyk-pyproject {
+          inherit uv2nix;
+        };
+
         pyk-python310 = final.callPackage ./nix/pyk {
-          inherit pyproject-nix pyproject-build-systems uv2nix;
+          inherit pyproject-nix pyproject-build-systems pyk-pyproject;
           python = final."python310";
         };
         pyk-python311 = final.callPackage ./nix/pyk {
-          inherit pyproject-nix pyproject-build-systems uv2nix;
+          inherit pyproject-nix pyproject-build-systems pyk-pyproject;
           python = final."python311";
         };
         pyk = pyk-python310;
@@ -204,7 +208,7 @@
           pkgs.lib.removeSuffix "\n" (builtins.readFile ./package/version);
 
         packages = rec {
-          inherit (pkgs) k k-lock pyk pyk-python310 pyk-python311 maven;
+          inherit (pkgs) k k-lock pyk pyk-python310 pyk-python311 pyk-pyproject maven;
 
           check-submodules = rv-nix-tools.lib.check-submodules pkgs {
             inherit llvm-backend haskell-backend;
@@ -248,6 +252,7 @@
                 substituteInPlace tests/regression-new/append/kparse-twice \
                   --replace '"$(dirname "$0")/../../../bin/kparse"' '"${k}/bin/kparse"'
               '';
+
               buildFlags = [
                 "K_BIN=${k}/bin"
                 "KLLVMLIB=${k}/lib/kllvm"
@@ -295,6 +300,11 @@
         overlays.default = final: prev: {
           inherit (self.packages.${final.system}) k;
         };
+        # this pyproject-nix overlay allows for overriding the python packages that are otherwise locked in `uv.lock`
+        # by using this overlay in dependant nix flakes, you ensure that nix overrides also override the python package         
+        overlays.pyk-pyproject = system: final: prev: {
+          inherit (self.packages.${system}.pyk-pyproject.lockFileOverlay final prev) kframework;
+        };
 
         # deprecated flake overlay output, please use `overlays.default` or `overlays.pyk` instead
         overlay = nixpkgs.lib.composeManyExtensions allOverlays;

nix/pyk-pyproject/default.nix

@@ -0,0 +1,29 @@
+{
+  lib,
+  callPackage,
+  nix-gitignore,
+
+  uv2nix,
+}:
+let
+  # load a uv workspace from a workspace root
+  workspace = uv2nix.lib.workspace.loadWorkspace {
+    workspaceRoot = lib.cleanSource (nix-gitignore.gitignoreSourcePure [
+        ../../.gitignore
+        ".github/"
+        "result*"
+        "/deps/"
+        # do not include submodule directories that might be initilized empty or non-existent
+      ] ../../pyk/.
+    );
+  };
+
+  # create overlay
+  lockFileOverlay = workspace.mkPyprojectOverlay {
+    # prefer "wheel" over "sdist" due to maintance overhead
+    # there is no bundled set of overlays for "sdist" in uv2nix, in contrast to poetry2nix
+    sourcePreference = "wheel";
+  };
+in {
+  inherit lockFileOverlay workspace;
+}

nix/pyk/default.nix

@@ -1,39 +1,21 @@
 {
   lib,
   callPackage,
-  nix-gitignore,
 
-  pyproject-nix,
   pyproject-build-systems,
-  uv2nix,
+  pyproject-nix,
+  pyk-pyproject,
 
-  python
+  python,
 }:
 let
+  inherit (pyk-pyproject) lockFileOverlay workspace;
+
   pyproject-util = callPackage pyproject-nix.build.util {};
   pyproject-packages = callPackage pyproject-nix.build.packages {
     inherit python;
   };
 
-  # load a uv workspace from a workspace root
-  workspace = uv2nix.lib.workspace.loadWorkspace {
-    workspaceRoot = lib.cleanSource (nix-gitignore.gitignoreSourcePure [
-        ../../.gitignore
-        ".github/"
-        "result*"
-        "/deps/"
-        # do not include submodule directories that might be initilized empty or non-existent
-      ] ../../pyk/.
-    );
-  };
-
-  # create overlay
-  lockFileOverlay = workspace.mkPyprojectOverlay {
-    # prefer "wheel" over "sdist" due to maintance overhead
-    # there is no bundled set of overlays for "sdist" in uv2nix, in contrast to poetry2nix
-    sourcePreference = "wheel";
-  };
-
   buildSystemsOverlay = import ./build-systems-overlay.nix;
 
   # construct package set
@@ -45,7 +27,8 @@ let
     # add build system overrides to certain python packages
     buildSystemsOverlay
   ]);
-in pyproject-util.mkApplication {
+in
+pyproject-util.mkApplication {
   # default dependancy group enables no optional dependencies and no dependency-groups
   venv = pythonSet.mkVirtualEnv "pyk-env" workspace.deps.default;
   package = pythonSet.kframework;