From 7f7455fa081da6c34cce0cb43dd9e1de2236a49c Mon Sep 17 00:00:00 2001
From: Henry Schreiner <HenrySchreinerIII@gmail.com>
Date: Fri, 20 Aug 2021 22:56:12 -0400
Subject: [PATCH 1/2] REF: use oldest-supported-numpy

This code is currently hand-copied from SciPy, now there's a package that exists to do just that. As a bonus, NumPy will no longer need to build wheels on 3.10 (Linux 64-bit only currently)
---
 pyproject.toml | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 03c1485bd4e35..4398046fc4bc7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,17 +5,9 @@ requires = [
     "setuptools>=51.0.0",
     "wheel",
     "Cython>=0.29.21,<3",  # Note: sync with setup.py
-    # Numpy requirements for different OS/architectures
-    # Copied from https://github.com/scipy/scipy/blob/master/pyproject.toml (which is also licensed under BSD)
-    "numpy==1.17.3; python_version=='3.7' and (platform_machine!='arm64' or platform_system!='Darwin') and platform_machine!='aarch64'",
-    "numpy==1.18.3; python_version=='3.8' and (platform_machine!='arm64' or platform_system!='Darwin') and platform_machine!='aarch64'",
-    "numpy==1.19.3; python_version>='3.9' and (platform_machine!='arm64' or platform_system!='Darwin') and platform_machine!='aarch64'",
-    # Aarch64(Python 3.9 requirements are the same as AMD64)
-    "numpy==1.19.2; python_version=='3.7' and platform_machine=='aarch64'",
-    "numpy==1.19.2; python_version=='3.8' and platform_machine=='aarch64'",
-    # Darwin Arm64
-    "numpy>=1.20.0; python_version=='3.8' and platform_machine=='arm64' and platform_system=='Darwin'",
-    "numpy>=1.20.0; python_version=='3.9' and platform_machine=='arm64' and platform_system=='Darwin'"
+    # Numpy requirements for different OS/architectures, see
+    # https://github.com/scipy/oldest-supported-numpy/blob/master/setup.cfg
+    "oldest-supported-numpy>=0.10",
 ]
 # uncomment to enable pep517 after versioneer problem is fixed.
 # https://github.com/python-versioneer/python-versioneer/issues/193

From b37784c36ba15a7ac93e5295137533a4a6dd4723 Mon Sep 17 00:00:00 2001
From: Henry Schreiner <henryschreineriii@gmail.com>
Date: Sat, 21 Aug 2021 11:39:18 -0400
Subject: [PATCH 2/2] CI: pin oldest supported NumPy

---
 .github/workflows/sdist.yml | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/sdist.yml b/.github/workflows/sdist.yml
index 2e890506073a8..600283193dc6e 100644
--- a/.github/workflows/sdist.yml
+++ b/.github/workflows/sdist.yml
@@ -58,7 +58,16 @@ jobs:
     - name: Install pandas from sdist
       run: |
         conda list
-        python -m pip install dist/*.gz
+        python -m pip install dist/*.gz -v
+
+    - name: Force oldest supported NumPy
+      run: |
+        case "${{matrix.python-version}}" in
+        3.8)
+          pip install numpy==1.17.3 ;;
+        3.9)
+          pip install numpy==1.19.3 ;;
+        esac
 
     - name: Import pandas
       run: |