Drop Python < 3.10 support

Python 3.10 is the default in Jammy, while Debian Bookworm has 3.11.
Since we dropped CI for older releases, we need to remove compatibility
code that won't be exercised in the tests.

README.md

@@ -24,6 +24,15 @@ Please see https://wiki.ubuntu.com/Apport for more details and further links.
 The files in [doc/](./doc/) document particular details such as package hooks,
 crash database configuration, or the internal data format.
 
+Platform requirements
+---------------------
+
+The absolute minimum requirements for your distribution are Python 3.10 or
+above. Depending on which features you want enabled, various Python packages
+also need to be available.
+
+TODO: document the Python dependencies
+
 Temporarily enabling apport
 ===========================
 

apport/packaging.py

@@ -9,53 +9,10 @@
 # option) any later version.  See http://www.gnu.org/copyleft/gpl.html for
 # the full text of the license.
 
+import platform
 import re
 import subprocess
 import sys
-import typing
-
-try:
-    from platform import freedesktop_os_release
-except ImportError:  # Python < 3.10
-
-    def _parse_os_release(*os_release_files: str) -> typing.Dict[str, str]:
-        """Parse os-release and return a parameter dictionary.
-
-        This function will behave identical to
-        platform.freedesktop_os_release() from Python >= 3.10, if
-        called with ("/etc/os-release", "/usr/lib/os-release").
-
-        See http://www.freedesktop.org/software/systemd/man/os-release.html
-        for specification of the file format.
-        """
-        # These fields are mandatory fields with well-known defaults
-        # in practice all Linux distributions override NAME, ID, and
-        # PRETTY_NAME.
-        ret = {"NAME": "Linux", "ID": "linux", "PRETTY_NAME": "Linux"}
-
-        errno = None
-        for filename in os_release_files:
-            try:
-                with open(filename, encoding="utf-8") as release_file:
-                    regex = re.compile("^([\\w]+)=(?:'|\")?(.*?)(?:'|\")?$")
-                    for line in release_file:
-                        match = regex.match(line.strip())
-                        if match:
-                            # Shell special characters ("$", quotes, backslash,
-                            # backtick) are escaped with backslashes
-                            ret[match.group(1)] = re.sub(
-                                r'\\([$"\'\\`])', r"\1", match.group(2)
-                            )
-                break
-            except OSError as error:
-                errno = error.errno
-        else:
-            raise OSError(errno, f"Unable to read files {', '.join(os_release_files)}")
-
-        return ret
-
-    def freedesktop_os_release() -> typing.Dict[str, str]:
-        return _parse_os_release("/etc/os-release", "/usr/lib/os-release")
 
 
 class PackageInfo:
@@ -379,7 +336,7 @@ def get_os_version(self):
             return self._os_version
 
         try:
-            info = freedesktop_os_release()
+            info = platform.freedesktop_os_release()
             name = self._sanitize_operating_system_name(info["NAME"])
             version = info.get("VERSION_ID")
             if name and version:

apport/packaging_impl/__init__.py

@@ -1,12 +1,13 @@
 import importlib
 import os
+import platform
 
-from apport.packaging import PackageInfo, freedesktop_os_release
+from apport.packaging import PackageInfo
 
 
 def determine_packaging_implementation() -> str:
     """Determine the packaging implementation for the host."""
-    info = freedesktop_os_release()
+    info = platform.freedesktop_os_release()
     assert info is not None
     ids = set([info["ID"]]) | set(info.get("ID_LIKE", "").split(" "))
     if "debian" in ids:

apport/packaging_impl/apt_dpkg.py

@@ -26,6 +26,7 @@
 import logging
 import os
 import pickle
+import platform
 import shutil
 import stat
 import subprocess
@@ -40,7 +41,7 @@
 import aptsources.sourceslist
 
 import apport.logging
-from apport.packaging import PackageInfo, freedesktop_os_release
+from apport.packaging import PackageInfo
 
 
 class __AptDpkgPackageInfo(PackageInfo):
@@ -1761,7 +1762,7 @@ def get_distro_codename(self):
         """Get "lsb_release -sc", cache the result."""
         if self._distro_codename is None:
             try:
-                info = freedesktop_os_release()
+                info = platform.freedesktop_os_release()
                 self._distro_codename = info["VERSION_CODENAME"]
             except (KeyError, OSError):
                 # Fall back to query lsb_release

tests/unit/test_packaging_impl.py

@@ -7,7 +7,7 @@
 
 
 class TestPackagingImpl(unittest.TestCase):
-    @unittest.mock.patch("apport.packaging_impl.freedesktop_os_release")
+    @unittest.mock.patch("platform.freedesktop_os_release")
     def test_determine_ubuntu(self, os_release_mock):
         os_release_mock.return_value = {
             "PRETTY_NAME": "Ubuntu 22.04.1 LTS",
@@ -21,7 +21,7 @@ def test_determine_ubuntu(self, os_release_mock):
         self.assertEqual(determine_packaging_implementation(), "apt_dpkg")
         os_release_mock.assert_called_once_with()
 
-    @unittest.mock.patch("apport.packaging_impl.freedesktop_os_release")
+    @unittest.mock.patch("platform.freedesktop_os_release")
     def test_determine_debian_unstable(self, os_release_mock):
         os_release_mock.return_value = {
             "PRETTY_NAME": "Debian GNU/Linux bookworm/sid",