python312Packages.pandas: Allow building with Numpy 1

pkgs/development/python-modules/pandas/default.nix

@@ -84,8 +84,20 @@ let
       })
     ];
 
+    # A NOTE regarding the Numpy version relaxing: Both Numpy versions 1.x &
+    # 2.x are supported. However upstream wants to always build with Numpy 2,
+    # and with it to still be able to run with a Numpy 1 or 2. We insist to
+    # perform this substitution even though python3.pkgs.numpy is of version 2
+    # nowadays, because our ecosystem unfortunately doesn't allow easily
+    # separating runtime and build-system dependencies. See also:
+    #
+    # https://discourse.nixos.org/t/several-comments-about-priorities-and-new-policies-in-the-python-ecosystem/51790
+    #
+    # Being able to build (& run) with Numpy 1 helps for python environments
+    # that override globally the `numpy` attribute to point to `numpy_1`.
     postPatch = ''
       substituteInPlace pyproject.toml \
+        --replace-fail "numpy>2.0.0,<2.5" numpy \
         --replace-fail "meson-python==0.13.1" "meson-python>=0.13.1" \
         --replace-fail "meson==1.2.1" "meson>=1.2.1"
     '';