Turn pyproject.toml patching into a hook

We should not be setting pre/post phases as it's counter intuitive
when working with overrides.

default.nix

@@ -82,18 +82,22 @@ let
           );
         in
           lockPkgs;
-
       overlays = builtins.map getFunctorFn (
         [
           (
-            self: super: {
-              mkPoetryDep = self.callPackage ./mk-poetry-dep.nix {
-                inherit pkgs lib python poetryLib;
-              };
-              poetry = poetryPkg;
-              # The canonical name is setuptools-scm
-              setuptools-scm = super.setuptools_scm;
-            }
+            self: super: let
+              hooks = self.callPackage ./hooks {};
+            in
+              {
+                mkPoetryDep = self.callPackage ./mk-poetry-dep.nix {
+                  inherit pkgs lib python poetryLib;
+                };
+                poetry = poetryPkg;
+                # The canonical name is setuptools-scm
+                setuptools-scm = super.setuptools_scm;
+
+                inherit (hooks) removePathDependenciesHook;
+              }
           )
           # Null out any filtered packages, we don't want python.pkgs from nixpkgs
           (self: super: builtins.listToAttrs (builtins.map (x: { name = x.name; value = null; }) incompatible))
@@ -187,15 +191,13 @@ let
 
           buildInputs = mkInput "buildInputs" buildSystemPkgs;
           propagatedBuildInputs = mkInput "propagatedBuildInputs" (getDeps "dependencies") ++ ([ py.pkgs.setuptools ]);
-          nativeBuildInputs = mkInput "nativeBuildInputs" [ pkgs.yj ];
+          nativeBuildInputs = mkInput "nativeBuildInputs" [ pkgs.yj py.pkgs.removePathDependenciesHook ];
           checkInputs = mkInput "checkInputs" (getDeps "dev-dependencies");
 
           passthru = {
             python = py;
           };
 
-          postPatch = (passedAttrs.postPatch or "") + poetryLib.removeTOMLPathDependencies python;
-
           meta = meta // {
             inherit (pyProject.tool.poetry) description homepage;
             license = getLicenseBySpdxId (pyProject.tool.poetry.license or "unknown");

hooks/default.nix

@@ -0,0 +1,25 @@
+{ python
+, callPackage
+, makeSetupHook
+, yj
+}:
+
+let
+  pythonInterpreter = python.pythonForBuild.interpreter;
+in
+{
+
+  removePathDependenciesHook = callPackage (
+    {}:
+      makeSetupHook {
+        name = "remove-path-dependencies.sh";
+        deps = [];
+        substitutions = {
+          inherit pythonInterpreter;
+          yj = "${yj}/bin/yj";
+          pyprojectPatchScript = "${./pyproject-without-path.py}";
+        };
+      } ./remove-path-dependencies.sh
+  ) {};
+
+}

hooks/remove-path-dependencies.sh

@@ -0,0 +1,8 @@
+remove-path-dependencies-hook() {
+    # Tell poetry not to resolve the path dependencies. Any version is fine!
+    @yj@ -tj < pyproject.toml | @pythonInterpreter@ @pyprojectPatchScript@ > pyproject.json
+    @yj@ -jt < pyproject.json > pyproject.toml
+    rm pyproject.json
+}
+
+postPatchHooks+=(remove-path-dependencies-hook)

lib.nix

@@ -93,14 +93,6 @@ let
         [ pythonPackages.${drvAttr} or (throw "unsupported build system ${buildSystem}") ]
       );
 
-  removeTOMLPathDependencies = python: ''
-    # Tell poetry not to resolve the path dependencies. Any version is
-    # fine !
-    ${pkgs.yj}/bin/yj -tj < pyproject.toml | ${python.interpreter} ${./pyproject-without-path.py} > pyproject.json
-    ${pkgs.yj}/bin/yj -jt < pyproject.json > pyproject.toml
-    rm pyproject.json
-  '';
-
 in
 {
   inherit
@@ -109,6 +101,5 @@ in
     isCompatible
     readTOML
     getBuildSystemPkgs
-    removeTOMLPathDependencies
     ;
 }

mk-poetry-dep.nix

@@ -107,7 +107,9 @@ pythonPackages.callPackage (
         dontStrip = format == "wheel";
 
         nativeBuildInputs = (if (!isSource && (getManyLinuxDeps fileInfo.name).str != null) then [ autoPatchelfHook ] else [])
-        ++ lib.optional (isLocal) pkgs.yj;
+        ++ lib.optional (isLocal) pkgs.yj
+        ++ lib.optional (format == "pyproject") pythonPackages.removePathDependenciesHook
+        ;
 
         buildInputs = (
           baseBuildInputs
@@ -120,8 +122,6 @@ pythonPackages.callPackage (
           # but dependencies try to access Django
           builtins.map (n: pythonPackages.${lib.toLower n}) (builtins.attrNames dependencies);
 
-        postPatch = (args.postPatch or "") + lib.optionalString isLocal (poetryLib.removeTOMLPathDependencies python);
-
         meta = {
           broken = ! isCompatible python.pythonVersion python-versions;
           license = [];