ensurepip failing on s390x 3.14.0a6 Alpine images

[tianon]

if test "xupgrade" != "xno" ; then \
	case upgrade in \
		upgrade) ensurepip="--upgrade" ;; \
		install|*) ensurepip="" ;; \
	esac; \
	LD_LIBRARY_PATH=/usr/src/python ./python -E -m ensurepip \
		$ensurepip --root=/ ; \
fi
Traceback (most recent call last):
 File "<string>", line 6, in <module>
 runpy.run_module("pip", run_name="__main__", alter_sys=True)
 ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 File "<frozen runpy>", line 226, in run_module
 File "<frozen runpy>", line 98, in _run_module_code
 File "<frozen runpy>", line 88, in _run_code
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/__main__.py", line 22, in <module>
 from pip._internal.cli.main import main as _main
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_internal/cli/main.py", line 11, in <module>
 from pip._internal.cli.autocompletion import autocomplete
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_internal/cli/autocompletion.py", line 10, in <module>
 from pip._internal.cli.main_parser import create_main_parser
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_internal/cli/main_parser.py", line 9, in <module>
 from pip._internal.build_env import get_runnable_pip
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_internal/build_env.py", line 17, in <module>
 from pip._internal.cli.spinners import open_spinner
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_internal/cli/spinners.py", line 9, in <module>
 from pip._internal.utils.logging import get_indentation
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_internal/utils/logging.py", line 29, in <module>
 from pip._internal.utils.misc import ensure_dir
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_internal/utils/misc.py", line 37, in <module>
 from pip._vendor.packaging.requirements import Requirement
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_vendor/packaging/requirements.py", line 8, in <module>
 from ._parser import parse_requirement as _parse_requirement
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_vendor/packaging/_parser.py", line 12, in <module>
 from ._tokenizer import DEFAULT_RULES, Tokenizer
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_vendor/packaging/_tokenizer.py", line 8, in <module>
 from .specifiers import Specifier
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_vendor/packaging/specifiers.py", line 18, in <module>
 from .utils import canonicalize_version
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_vendor/packaging/utils.py", line 11, in <module>
 from .tags import Tag, parse_tag
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_vendor/packaging/tags.py", line 23, in <module>
 from . import _manylinux, _musllinux
 File "/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl/pip/_vendor/packaging/_manylinux.py", line 12, in <module>
 from ._elffile import EIClass, EIData, ELFFile, EMachine
 File "<frozen importlib._bootstrap>", line 1368, in _find_and_load
 File "<frozen importlib._bootstrap>", line 1330, in _find_and_load_unlocked
 File "<frozen importlib._bootstrap>", line 1264, in _find_spec
 File "<frozen importlib._bootstrap_external>", line 1295, in find_spec
 File "<frozen importlib._bootstrap_external>", line 1269, in _get_spec
 File "<frozen zipimport>", line 110, in find_spec
 File "<frozen importlib._bootstrap>", line 675, in spec_from_loader
 File "<frozen importlib._bootstrap_external>", line 583, in spec_from_file_location
 File "<frozen zipimport>", line 171, in get_filename
 File "<frozen zipimport>", line 810, in _get_module_code
 File "<frozen zipimport>", line 739, in _compile_source
MemoryError: Parser stack overflowed - Python source too complex to parse
Traceback (most recent call last):
 File "<frozen runpy>", line 198, in _run_module_as_main
 File "<frozen runpy>", line 88, in _run_code
 File "/usr/src/python/Lib/ensurepip/__main__.py", line 5, in <module>
 sys.exit(ensurepip._main())
 ~~~~~~~~~~~~~~~^^
 File "/usr/src/python/Lib/ensurepip/__init__.py", line 257, in _main
 return _bootstrap(
 root=args.root,
 ...<4 lines>...
 default_pip=args.default_pip,
 )
 File "/usr/src/python/Lib/ensurepip/__init__.py", line 172, in _bootstrap
 return _run_pip([*args, "pip"], [os.fsdecode(tmp_wheel_path)])
 File "/usr/src/python/Lib/ensurepip/__init__.py", line 87, in _run_pip
 return subprocess.run(cmd, check=True).returncode
 ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
 File "/usr/src/python/Lib/subprocess.py", line 577, in run
 raise CalledProcessError(retcode, process.args,
 output=stdout, stderr=stderr)
subprocess.CalledProcessError: Command '['/usr/src/python/python', '-W', 'ignore::DeprecationWarning', '-c', '\nimport runpy\nimport sys\nsys.path = [\'/tmp/tmp29e5ljf7/pip-25.0.1-py3-none-any.whl\'] + sys.path\nsys.argv[1:] = [\'install\', \'--no-cache-dir\', \'--no-index\', \'--find-links\', \'/tmp/tmp29e5ljf7\', \'--root\', \'/\', \'--upgrade\', \'pip\']\nrunpy.run_module("pip", run_name="__main__", alter_sys=True)\n']' returned non-zero exit status 1.
make: *** [Makefile:2365: install] Error 1

This is failing on both Alpine 3.20 and 3.21, and isn't failing for any other architecture+os+version combo.

[tianon]

Given how esoteric the issue is, I'm kind of inclined to just disable Alpine variants entirely for s390x on 3.14(+), but I'm open to other thoughts.

[tianon]

The only meaningful Google result for "Parser stack overflowed - Python source too complex to parse" is python/cpython#131770, which is clearly unrelated.

[tianon]

The definition of MAXSTACK isn't obviously compiler, architecture, or OS dependent: https://github.com/python/cpython/blob/77b2c933cab4f38a8ce1f7633b96ba213566d306/Tools/peg_generator/pegen/c_generator.py#L47

(used down in https://github.com/python/cpython/blob/77b2c933cab4f38a8ce1f7633b96ba213566d306/Tools/peg_generator/pegen/c_generator.py#L382-L386, which is what prints this error)

[tianon]

It was an extreme long shot, but I bumped that 4000 up to 8000 and it didn't fix it (and to be clear, I didn't really expect it to), so something extra strange is definitely happening here.