Drop Python 3.8 support

The pypa/manylinux project removed CPython 3.8 from manylinux_2_28
on 2026-05-07, breaking the test-build-wheel-manylinux (3.8) job
(/usr/bin/python3 fallback has no pip). 3.8 has been EOL since
Oct 2024, so drop it everywhere: CI matrices, requires-python /
classifiers in pyproject.toml, and the now-dead Path.is_relative_to
polyfill in importer.py.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jaltmayerpizzorno

.github/workflows/build-and-upload.yml

@@ -30,7 +30,7 @@ jobs:
     container: ${{ matrix.container }}
     strategy:
       matrix:
-        python_version: ['3.8', '3.9', '3.10']  # The 3.10 builds use abi3, so are good for Python 3.10+
+        python_version: ['3.9', '3.10']  # The 3.10 builds use abi3, so are good for Python 3.10+
         os: ['ubuntu-latest', 'macos-13', 'macos-14', 'windows-latest']
         include:
           - os: ubuntu-latest

.github/workflows/tests.yml

@@ -20,10 +20,8 @@ jobs:
       fail-fast: false
       matrix:
         os: [ ubuntu-latest, macos-latest, windows-latest ]
-        python: [ '3.8', '3.9', 'pypy-3.9', '3.10', 'pypy-3.10', '3.11', '3.12', '3.13', '3.14' ]
+        python: [ '3.9', 'pypy-3.9', '3.10', 'pypy-3.10', '3.11', '3.12', '3.13', '3.14' ]
         exclude:
-          - os: macos-latest  # Python 3.8 unavailable on macos-14
-            python: '3.8'
           - os: macos-latest  # Python 3.9 unavailable on macos-14
             python: '3.9'
 
@@ -97,7 +95,7 @@ jobs:
     container: ${{ matrix.container }}
     strategy:
       matrix:
-        python_version: ['3.8', '3.9', '3.10', '3.11']  # 3.12+ are "pure Python", no need to build on manylinux
+        python_version: ['3.9', '3.10', '3.11']  # 3.12+ are "pure Python", no need to build on manylinux; 3.8 was removed from the manylinux image (2026-05-07)
         include:
           - os: ubuntu-latest
             container: quay.io/pypa/manylinux_2_28_x86_64 # https://github.com/pypa/manylinux

pyproject.toml

@@ -8,7 +8,6 @@ authors = [
     { name="Emery Berger", email="emery.berger@gmail.com" }
 ]
 classifiers = [
-    "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
@@ -20,7 +19,7 @@ classifiers = [
     "Operating System :: MacOS :: MacOS X",
     "Operating System :: Microsoft :: Windows :: Windows 10"
 ]
-requires-python = ">=3.8,<3.15"
+requires-python = ">=3.9,<3.15"
 dependencies = [
     "tabulate"
 ]

src/slipcover/importer.py

@@ -17,14 +17,6 @@
     from importlib.abc import ResourceReader as TraversableResources
 
 
-if sys.version_info[0:2] < (3,9):
-    # Path.is_relative_to is new in Python 3.9
-    def is_relative_to(self: Path, other: str) -> bool:
-        other = Path(other)
-        return other == self or other in self.parents
-    setattr(Path, 'is_relative_to', is_relative_to)
-
-
 class SlipcoverLoader(Loader):
     def __init__(self, sci: Slipcover, orig_loader: Loader, origin: str):
         self.sci = sci                  # Slipcover object measuring coverage