Moved the dependencies to a 'core' extra to avoid dangers with cyclic…

… dependencies at build time.

newsfragments/2825.removal.rst

@@ -1 +1 @@
-Now setuptools declares its own dependencies. Dependencies are still vendored for bootstrapping purposes, but installed dependencies are preferred. Downstream packagers can de-vendor by simply removing the ``setuptools/_vendor`` directory.
+Now setuptools declares its own dependencies in the ``core`` extra. Dependencies are still vendored for bootstrapping purposes, but installed dependencies are preferred. Downstream packagers can de-vendor by simply removing the ``setuptools/_vendor`` directory.

pyproject.toml

@@ -25,17 +25,6 @@ classifiers = [
 keywords = ["CPAN PyPI distutils eggs package management"]
 requires-python = ">=3.8"
 dependencies = [
-	"packaging>=24",
-	"ordered-set>=3.1.1",
-	"more_itertools>=8.8",
-	"jaraco.text>=3.7",
-	"importlib_resources>=5.10.2",
-	"importlib_metadata>=6",
-	"tomli>=2.0.1",
-	"wheel>=0.43.0",
-
-	# pkg_resources
-	"platformdirs >= 2.6.2",
 ]
 
 [project.urls]
@@ -107,6 +96,19 @@ doc = [
 ]
 ssl = []
 certs = []
+core = [
+	"packaging>=24",
+	"ordered-set>=3.1.1",
+	"more_itertools>=8.8",
+	"jaraco.text>=3.7",
+	"importlib_resources>=5.10.2",
+	"importlib_metadata>=6",
+	"tomli>=2.0.1",
+	"wheel>=0.43.0",
+
+	# pkg_resources
+	"platformdirs >= 2.6.2",
+]
 
 [project.entry-points."distutils.commands"]
 alias = "setuptools.command.alias:alias"

tools/vendored.py

@@ -1,4 +1,5 @@
 import functools
+import re
 import sys
 import subprocess
 
@@ -29,11 +30,18 @@ def metadata():
     return jaraco.packaging.metadata.load('.')
 
 
+def upgrade_core(dep):
+    """
+    Remove 'extra == "core"' from any dependency.
+    """
+    return re.sub('''(;| and) extra == ['"]core['"]''', '', dep)
+
+
 def load_deps():
     """
-    Read the dependencies from `.`.
+    Read the dependencies from `.[core]`.
     """
-    return metadata().get_all('Requires-Dist')
+    return list(map(upgrade_core, metadata().get_all('Requires-Dist')))
 
 
 def min_python():

tox.ini

@@ -10,6 +10,7 @@ commands =
 usedevelop = True
 extras =
 	test
+	core
 pass_env =
 	SETUPTOOLS_USE_DISTUTILS
 	SETUPTOOLS_ENFORCE_DEPRECATION