Revamp Python build system to fix multiple build problems

.circleci/config.yml

@@ -9,8 +9,7 @@ jobs:
     steps:
       - checkout
       - run:
-          # TODO in-place pip install is not working
-          command: cd PythonAPI && python setup.py build_ext
+          command: python -m pip install --use-feature=in-tree-build ./PythonAPI
           name: Install From Source
 
   build-from-sdist:
@@ -19,8 +18,9 @@ jobs:
       - checkout
       - run:
           command: |
-            cd PythonAPI && python setup.py sdist
-            python -m pip install --progress-bar off dist/*.tar.gz
+            python -m pip install build
+            python -m build --sdist ./PythonAPI
+            python -m pip install --progress-bar off ./PythonAPI/dist/*.tar.gz
           name: Install From Distribution
       - run:
           command: |

PythonAPI/Makefile

@@ -5,5 +5,5 @@ all:
 
 install:
 	# install pycocotools to the Python site-packages
-	python setup.py build_ext install
+	python -m pip install --use-feature=in-tree-build .
 	rm -rf build

PythonAPI/pyproject.toml

@@ -0,0 +1,8 @@
+[build-system]
+requires = [
+    "cython>=0.27.3",
+    "oldest-supported-numpy",
+    "setuptools>=43.0.0",
+    "wheel",
+]
+build-backend = "setuptools.build_meta"

PythonAPI/setup.py

@@ -1,15 +1,8 @@
 """To compile and install locally run "python setup.py build_ext --inplace".
-To install library to Python site-packages run "python setup.py build_ext install"
+To install library to Python site-packages run "python -m pip install --use-feature=in-tree-build ."
 """
 import platform
-from setuptools import dist, setup, Extension
-
-setup_requires = [
-    'setuptools>=18.0',
-    'cython>=0.27.3',
-    'numpy',
-]
-dist.Distribution().fetch_build_eggs(setup_requires)
+from setuptools import setup, Extension
 
 import numpy as np
 
@@ -30,11 +23,10 @@
     license="FreeBSD",
     packages=['pycocotools'],
     package_dir={'pycocotools': 'pycocotools'},
-    setup_requires=setup_requires,
+    python_requires='>=3.5',
     install_requires=[
-        'setuptools>=18.0',
-        'cython>=0.27.3',
-        'matplotlib>=2.1.0'
+        'matplotlib>=2.1.0',
+        'numpy',
     ],
     version='2.0.2',
     ext_modules=ext_modules