The code in CPython uses XML_SetReparseDeferralEnabled when expat is >= 2.6 during the build.
However, when users upgrade Python independently on the expat package,
they may have expat 2.5 installed and see errors like:
$ python3.1X -m venv venv
Error: Command '['venv/bin/python3.1X', '-m', 'ensurepip', '--upgrade', '--default-pip']' returned non-zero exit status 1.
$ venv/bin/python3.1X -m ensurepip --upgrade --default-pip
Traceback (most recent call last):
...
File "/tmp/.../pip-24.0-py3-none-any.whl/pip/_internal/commands/install.py", line 15, in <module>
from pip._internal.cli.req_command import (
...<3 lines>...
)
File "/tmp/.../pip-24.0-py3-none-any.whl/pip/_internal/cli/req_command.py", line 21, in <module>
from pip._internal.index.package_finder import PackageFinder
File "/tmp/.../pip-24.0-py3-none-any.whl/pip/_internal/index/package_finder.py", line 30, in <module>
from pip._internal.req import InstallRequirement
File "/tmp/.../pip-24.0-py3-none-any.whl/pip/_internal/req/__init__.py", line 8, in <module>
from .req_install import InstallRequirement
File "/tmp/.../pip-24.0-py3-none-any.whl/pip/_internal/req/req_install.py", line 40, in <module>
from pip._internal.operations.install.wheel import install_wheel
File "/tmp/.../pip-24.0-py3-none-any.whl/pip/_internal/operations/install/wheel.py", line 39, in <module>
from pip._vendor.distlib.scripts import ScriptMaker
File "/tmp/.../pip-24.0-py3-none-any.whl/pip/_vendor/distlib/scripts.py", line 16, in <module>
from .compat import sysconfig, detect_encoding, ZipFile
File "/tmp/.../pip-24.0-py3-none-any.whl/pip/_vendor/distlib/compat.py", line 81, in <module>
import xmlrpc.client as xmlrpclib
File "/usr/lib64/python3.1X/xmlrpc/client.py", line 138, in <module>
from xml.parsers import expat
File "/usr/lib64/python3.1X/xml/parsers/expat.py", line 4, in <module>
from pyexpat import *
ImportError: /usr/lib64/python3.1X/lib-dynload/pyexpat.cpython-31X-x86_64-linux-gnu.so: undefined symbol: XML_SetReparseDeferralEnabled
Traceback (most recent call last):
...
subprocess.CalledProcessError: Command '['venv/bin/python3.1X', '-W', 'ignore::DeprecationWarning', '-c', '\nimport runpy\nimport sys\nsys.path = [\'/tmp/.../pip-24.0-py3-none-any.whl\'] + sys.path\nsys.argv[1:] = [\'install\', \'--no-cache-dir\', \'--no-index\', \'--find-links\', \'/tmp/...\', \'--upgrade\', \'pip\']\nrunpy.run_module("pip", run_name="__main__", alter_sys=True)\n']' returned non-zero exit status 1.
Thanks to Markus Falb for discovering this problem.
https://lists.fedoraproject.org/archives/list/python-devel@lists.fedoraproject.org/thread/7XHGWHBQDNFKNGSZTP44SSD6PQKZPG6C/
