buildPython*: restructure expression

Restructure the derivation to prepare for - fixed-point arguments support - overridePythonAttrs deprecation
NixOS · Jan 22, 2025 · b2644e7 · b2644e7
1 parent 16f0cec
commit b2644e7
Showing 1 changed file with 66 additions and 61 deletions.
diff --git a/pkgs/development/interpreters/python/mk-python-derivation.nix b/pkgs/development/interpreters/python/mk-python-derivation.nix
@@ -205,75 +205,85 @@ in
   ...
 }@attrs:
 
-let
-  format' =
-    assert (pyproject != null) -> (format == null);
-    if pyproject != null then
-      if pyproject then "pyproject" else "other"
-    else if format != null then
-      format
-    else
-      "setuptools";
-
-  withDistOutput = withDistOutput' format';
-
-  validatePythonMatches =
-    let
-      throwMismatch =
-        attrName: drv:
-        let
-          myName = "'${namePrefix}${name}'";
-          theirName = "'${drv.name}'";
-          optionalLocation =
-            let
-              pos = unsafeGetAttrPos (if attrs ? "pname" then "pname" else "name") attrs;
-            in
-            optionalString (pos != null) " at ${pos.file}:${toString pos.line}:${toString pos.column}";
-        in
-        throw ''
-          Python version mismatch in ${myName}:
+# This derivation transformation function must be independent to `attrs`
+# for fixed-point arguments support in the future.
+(
+  drv:
+  extendDerivation (
+    disabled
+    -> throw "${lib.removePrefix namePrefix drv.name} not supported for interpreter ${python.executable}"
+  ) { } (toPythonModule drv)
+)
+  (
+    stdenv.mkDerivation (
+      finalAttrs:
+      let
+        format' =
+          assert (pyproject != null) -> (format == null);
+          if pyproject != null then
+            if pyproject then "pyproject" else "other"
+          else if format != null then
+            format
+          else
+            "setuptools";
+
+        withDistOutput = withDistOutput' format';
+
+        validatePythonMatches =
+          let
+            throwMismatch =
+              attrName: drv:
+              let
+                myName = "'${namePrefix}${name}'";
+                theirName = "'${drv.name}'";
+                optionalLocation =
+                  let
+                    pos = unsafeGetAttrPos (if attrs ? "pname" then "pname" else "name") attrs;
+                  in
+                  optionalString (pos != null) " at ${pos.file}:${toString pos.line}:${toString pos.column}";
+              in
+              throw ''
+                Python version mismatch in ${myName}:
 
-          The Python derivation ${myName} depends on a Python derivation
-          named ${theirName}, but the two derivations use different versions
-          of Python:
+                The Python derivation ${myName} depends on a Python derivation
+                named ${theirName}, but the two derivations use different versions
+                of Python:
 
-              ${leftPadName myName theirName} uses ${python}
-              ${leftPadName theirName myName} uses ${toString drv.pythonModule}
+                    ${leftPadName myName theirName} uses ${python}
+                    ${leftPadName theirName myName} uses ${toString drv.pythonModule}
 
-          Possible solutions:
+                Possible solutions:
 
-            * If ${theirName} is a Python library, change the reference to ${theirName}
-              in the ${attrName} of ${myName} to use a ${theirName} built from the same
-              version of Python
+                  * If ${theirName} is a Python library, change the reference to ${theirName}
+                    in the ${attrName} of ${myName} to use a ${theirName} built from the same
+                    version of Python
 
-            * If ${theirName} is used as a tool during the build, move the reference to
-              ${theirName} in ${myName} from ${attrName} to nativeBuildInputs
+                  * If ${theirName} is used as a tool during the build, move the reference to
+                    ${theirName} in ${myName} from ${attrName} to nativeBuildInputs
 
-            * If ${theirName} provides executables that are called at run time, pass its
-              bin path to makeWrapperArgs:
+                  * If ${theirName} provides executables that are called at run time, pass its
+                    bin path to makeWrapperArgs:
 
-                  makeWrapperArgs = [ "--prefix PATH : ''${lib.makeBinPath [ ${getName drv} ] }" ];
+                        makeWrapperArgs = [ "--prefix PATH : ''${lib.makeBinPath [ ${getName drv} ] }" ];
 
-          ${optionalLocation}
-        '';
+                ${optionalLocation}
+              '';
 
-      checkDrv =
-        attrName: drv:
-        if (isPythonModule drv) && (isMismatchedPython drv) then throwMismatch attrName drv else drv;
+            checkDrv =
+              attrName: drv:
+              if (isPythonModule drv) && (isMismatchedPython drv) then throwMismatch attrName drv else drv;
 
-    in
-    attrName: inputs: map (checkDrv attrName) inputs;
+          in
+          attrName: inputs: map (checkDrv attrName) inputs;
 
-  isBootstrapInstallPackage = isBootstrapInstallPackage' (attrs.pname or null);
+        isBootstrapInstallPackage = isBootstrapInstallPackage' (attrs.pname or null);
 
-  isBootstrapPackage = isBootstrapInstallPackage || isBootstrapPackage' (attrs.pname or null);
+        isBootstrapPackage = isBootstrapInstallPackage || isBootstrapPackage' (attrs.pname or null);
 
-  isSetuptoolsDependency = isSetuptoolsDependency' (attrs.pname or null);
+        isSetuptoolsDependency = isSetuptoolsDependency' (attrs.pname or null);
 
-  # Keep extra attributes from `attrs`, e.g., `patchPhase', etc.
-  self = toPythonModule (
-    stdenv.mkDerivation (
-      finalAttrs:
+      in
+      # Keep extra attributes from `attrs`, e.g., `patchPhase', etc.
       (cleanAttrs attrs)
       // {
 
@@ -449,9 +459,4 @@ let
         }
       )
     )
-  );
-
-in
-extendDerivation (
-  disabled -> throw "${name} not supported for interpreter ${python.executable}"
-) { } self
+  )