Emit a SetuptoolsDeprecationWarning when setup_requires is used. Ref #2823.debt/deprecate-setup-requires

1 files changed, 6 insertions, 0 deletions

diff --git a/setuptools/__init__.py b/setuptools/__init__.py
index 9d6f0bc0..a623262e 100644
--- a/setuptools/__init__.py
+++ b/setuptools/__init__.py
@@ -4,6 +4,7 @@ from fnmatch import fnmatchcase
 import functools
 import os
 import re
+import warnings
 
 import _distutils_hack.override  # noqa: F401
 
@@ -144,6 +145,11 @@ def _install_setup_requires(attrs):
     # Honor setup.cfg's options.
     dist.parse_config_files(ignore_option_errors=True)
     if dist.setup_requires:
+        warnings.warn(
+            "setup_requires is deprecated. Supply build "
+            "dependencies using PEP 517 pyproject.toml build-requires.",
+            SetuptoolsDeprecationWarning,
+        )
         dist.fetch_build_eggs(dist.setup_requires)