Merge pull request #100 from micro-manager/swig-from-pypi

Use SWIG from PyPI as build requirement

maintainer-notes.md

@@ -101,6 +101,8 @@ and the binary wheels attached.
 
 - The minimum version of python supported is declared in `pypyproject.toml`,
   in the `[project.requires-python]` section.
+- SWIG 4.x is required and automatically fetched via `pyproject.toml` under
+  `[build-system.requires]`.
 - The build-time versions of numpy are in `pyproject.toml`, in the
   `[build-system.requires]` section.
 - The run-time numpy dependency is declared in `pyproject.toml`, in the
@@ -112,10 +114,6 @@ and the binary wheels attached.
   built agains the oldest NumPy version that we claim to support. Thus, any
   issue with the build or our CI will limit the lowest supported versions.
 
-- Swig.
-  - Swig 4.x should be used.
-  - Swig 1.x generates code that is no longer compatible with Python 3.x.
-
 ## ABI Compatibility
 
 - The Python platform and ABI compatibility is all handled by the Wheel system.

pyproject.toml

@@ -2,6 +2,7 @@
 [build-system]
 requires = [
     "setuptools >=61.0.0",
+    "swig >=4",
     "numpy==1.14.5; python_version=='3.7'",
     "numpy==1.17.3; python_version=='3.8'",
     "numpy==1.19.3; python_version=='3.9'",