fix: tolerate invalid python requires

Signed-off-by: Frost Ming <[email protected]>

src/unearth/evaluator.py

@@ -21,7 +21,12 @@
 
 from unearth.link import Link
 from unearth.pep425tags import get_supported
-from unearth.utils import ARCHIVE_EXTENSIONS, splitext, strip_extras
+from unearth.utils import (
+    ARCHIVE_EXTENSIONS,
+    fix_legacy_specifier,
+    splitext,
+    strip_extras,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -151,7 +156,9 @@ def _check_requires_python(self, link: Link) -> None:
             py_ver = self.target_python.py_ver or sys.version_info[:2]
             py_version = ".".join(str(v) for v in py_ver)
             try:
-                requires_python = SpecifierSet(link.requires_python)
+                requires_python = SpecifierSet(
+                    fix_legacy_specifier(link.requires_python)
+                )
             except InvalidSpecifier:
                 raise LinkMismatchError(
                     f"Invalid requires-python: {link.requires_python}"

src/unearth/utils.py

@@ -4,8 +4,10 @@
 import functools
 import itertools
 import os
+import re
 import sys
 import urllib.parse as parse
+import warnings
 from pathlib import Path
 from typing import Iterable, Iterator, Sequence, TypeVar
 from urllib.request import pathname2url, url2pathname
@@ -217,3 +219,39 @@ def __getitem__(self, index: int) -> T:  # type: ignore[override]
             if i == index:
                 return item
         raise IndexError("Index out of range")
+
+
+_legacy_specifier_re = re.compile(r"(==|!=|<=|>=|<|>)(\s*)([^,;\s)]*)")
+
+
+@functools.lru_cache()
+def fix_legacy_specifier(specifier: str) -> str:
+    """Since packaging 22.0, legacy specifiers like '>=4.*' are no longer
+    supported. We try to normalize them to the new format.
+    """
+
+    def fix_wildcard(match: re.Match[str]) -> str:
+        operator, _, version = match.groups()
+        if operator in ("==", "!="):
+            return match.group(0)
+        if ".*" in version:
+            warnings.warn(
+                ".* suffix can only be used with `==` or `!=` operators",
+                FutureWarning,
+                stacklevel=4,
+            )
+            version = version.replace(".*", ".0")
+            if operator in ("<", "<="):  # <4.* and <=4.* are equivalent to <4.0
+                operator = "<"
+            elif operator in (">", ">="):  # >4.* and >=4.* are equivalent to >=4.0
+                operator = ">="
+        elif "+" in version:  # Drop the local version
+            warnings.warn(
+                "Local version label can only be used with `==` or `!=` operators",
+                FutureWarning,
+                stacklevel=4,
+            )
+            version = version.split("+")[0]
+        return f"{operator}{version}"
+
+    return _legacy_specifier_re.sub(fix_wildcard, specifier)

tests/test_evaluator.py

@@ -210,6 +210,7 @@ def test_retrieve_hash_from_internet(pypi, session, url):
     )
 
 
+@pytest.mark.filterwarnings("ignore::FutureWarning")
 @pytest.mark.parametrize(
     "link,expected",
     [
@@ -226,6 +227,13 @@ def test_retrieve_hash_from_internet(pypi, session, url):
             ),
             False,
         ),
+        (
+            Link(
+                "https://test.pypi.org/files/click-8.1.3-py3-none-any.whl",
+                requires_python=">3.6.*",
+            ),
+            True,
+        ),
     ],
 )
 @pytest.mark.parametrize("ignore_compatibility", (True, False))