ok, no numpy 2 yet

pyproject.toml

@@ -5,7 +5,22 @@ requires = [
     "setuptools_scm >= 8.0",
     "Cython>=3.0.8",
     # Below copied from scipy https://github.com/scipy/scipy/blob/main/pyproject.toml
-    "numpy>=2.0.0rc1",
+
+    # default numpy requirements
+    "numpy==1.22.4; python_version<='3.10' and platform_python_implementation != 'PyPy'",
+    "numpy==1.23.2; python_version=='3.11' and platform_python_implementation != 'PyPy'",
+    "numpy>=1.26.0,<1.27; python_version=='3.12'",
+
+    # PyPy requirements; 1.25.0 was the first version to have pypy-3.9 wheels,
+    # and 1.25.0 also changed the C API target to 1.19.x, so no longer a need
+    # for an exact pin.
+    "numpy>=1.25.0; python_version>='3.9' and platform_python_implementation=='PyPy'",
+
+    # For Python versions which aren't yet officially supported, we specify an
+    # unpinned NumPy which allows source distributions to be used and allows
+    # wheels to be used as soon as they become available.
+    # Python 3.13 has known issues that are only fixed in numpy 2.0.0.dev0
+    "numpy>=2.0.0.dev0; python_version>='3.13'",
 ]
 build-backend = "setuptools.build_meta"