Removed install dependency on setuptools (#483)

Also re-added the fallback for `license_paths` on setuptools versions older than 57.

docs/news.rst

@@ -1,6 +1,10 @@
 Release Notes
 =============
 
+**UNRELEASED**
+
+- Removed install dependency on setuptools
+
 **0.38.0 (2022-10-21)**
 
 - Dropped support for Python < 3.7

setup.cfg

@@ -32,7 +32,7 @@ package_dir=
     = src
 packages = find:
 python_requires = >=3.7
-install_requires = setuptools >= 57.0.0
+setup_requires = setuptools >= 45.2.0
 zip_safe = False
 
 [options.packages.find]

src/wheel/bdist_wheel.py

@@ -15,6 +15,7 @@
 import warnings
 from collections import OrderedDict
 from email.generator import BytesGenerator, Generator
+from glob import iglob
 from io import BytesIO
 from shutil import rmtree
 from zipfile import ZIP_DEFLATED, ZIP_STORED
@@ -31,6 +32,9 @@
 
 safe_name = pkg_resources.safe_name
 safe_version = pkg_resources.safe_version
+setuptools_major_version = int(
+    pkg_resources.get_distribution("setuptools").version.split(".")[0]
+)
 
 PY_LIMITED_API_PATTERN = r"cp3\d"
 
@@ -430,8 +434,47 @@ def _ensure_relative(self, path):
 
     @property
     def license_paths(self):
-        metadata = self.distribution.metadata
-        return sorted(metadata.license_files or [])
+        if setuptools_major_version >= 57:
+            # Setuptools has resolved any patterns to actual file names
+            return self.distribution.metadata.license_files or ()
+
+        files = set()
+        metadata = self.distribution.get_option_dict("metadata")
+        if setuptools_major_version >= 42:
+            # Setuptools recognizes the license_files option but does not do globbing
+            patterns = self.distribution.metadata.license_files
+        else:
+            # Prior to those, wheel is entirely responsible for handling license files
+            if "license_files" in metadata:
+                patterns = metadata["license_files"][1].split()
+            else:
+                patterns = ()
+
+        if "license_file" in metadata:
+            warnings.warn(
+                'The "license_file" option is deprecated. Use "license_files" instead.',
+                DeprecationWarning,
+            )
+            files.add(metadata["license_file"][1])
+
+        if not files and not patterns and not isinstance(patterns, list):
+            patterns = ("LICEN[CS]E*", "COPYING*", "NOTICE*", "AUTHORS*")
+
+        for pattern in patterns:
+            for path in iglob(pattern):
+                if path.endswith("~"):
+                    log.debug(
+                        f'ignoring license file "{path}" as it looks like a backup'
+                    )
+                    continue
+
+                if path not in files and os.path.isfile(path):
+                    log.info(
+                        f'adding license file "{path}" (matched pattern "{pattern}")'
+                    )
+                    files.add(path)
+
+        return files
 
     def egg2dist(self, egginfo_path, distinfo_path):
         """Convert an .egg-info directory into a .dist-info directory"""

src/wheel/cli/convert.py

@@ -7,12 +7,15 @@
 import zipfile
 from glob import iglob
 
-from setuptools.dist import Distribution
-
 from ..bdist_wheel import bdist_wheel
 from ..wheelfile import WheelFile
 from . import WheelError
 
+try:
+    from setuptools import Distribution
+except ImportError:
+    from distutils.dist import Distribution
+
 egg_info_re = re.compile(
     r"""
     (?P<name>.+?)-(?P<ver>.+?)

tests/test_bdist_wheel.py

@@ -84,6 +84,17 @@ def test_licenses_default(dummy_dist, monkeypatch, tmpdir):
         assert set(wf.namelist()) == DEFAULT_FILES | license_files
 
 
+def test_licenses_deprecated(dummy_dist, monkeypatch, tmpdir):
+    dummy_dist.join("setup.cfg").write("[metadata]\nlicense_file=licenses/DUMMYFILE")
+    monkeypatch.chdir(dummy_dist)
+    subprocess.check_call(
+        [sys.executable, "setup.py", "bdist_wheel", "-b", str(tmpdir), "--universal"]
+    )
+    with WheelFile("dist/dummy_dist-1.0-py2.py3-none-any.whl") as wf:
+        license_files = {"dummy_dist-1.0.dist-info/DUMMYFILE"}
+        assert set(wf.namelist()) == DEFAULT_FILES | license_files
+
+
 @pytest.mark.parametrize(
     "config_file, config",
     [