Hi~ I’m upgrading from pants 1.25.0 to 1.26.0.

./pants --version

works fine, but when I build my binary, I encounter this error:

ERROR: Command errored out with exit status 1:
   command: /usr/bin/python2.7 /tmp/tmp35l8p0cf/.deps/pip/pip/_vendor/pep517/_in_process.py get_requires_for_build_wheel /tmp/tmpPhYaZM
       cwd: /tmp/pip-download-Ku1TIN/gevent
  Complete output (10 lines):
  Traceback (most recent call last):
    File "/tmp/tmp35l8p0cf/.deps/pip/pip/_vendor/pep517/_in_process.py", line 257, in <module>
      main()
    File "/tmp/tmp35l8p0cf/.deps/pip/pip/_vendor/pep517/_in_process.py", line 240, in main
      json_out['return_val'] = hook(**hook_input['kwargs'])
    File "/tmp/tmp35l8p0cf/.deps/pip/pip/_vendor/pep517/_in_process.py", line 85, in get_requires_for_build_wheel
      backend = _build_backend()
    File "/tmp/tmp35l8p0cf/.deps/pip/pip/_vendor/pep517/_in_process.py", line 76, in _build_backend
      obj = getattr(obj, path_part)
  AttributeError: 'module' object has no attribute '__legacy__'
  ----------------------------------------
ERROR: Command errored out with exit status 1: /usr/bin/python2.7 /tmp/tmp35l8p0cf/.deps/pip/pip/_vendor/pep517/_in_process.py get_requires_for_build_wheel /tmp/tmpPhYaZM Check the logs for full command output.
19:05:57 [DEBUG] pants.process.lock:pid=7609: releasing lock: <pants.process.lock.OwnerPrintingInterProcessFileLock object at 0x7d76780ecd68>

               Waiting for background workers to finish.
12:05:57 00:32   [complete]
               FAILURE
timestamp: 2022-04-03T12:05:57.308688
Exception caught: (pex.resolver.Unsatisfiable)
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/bin/pants", line 8, in <module>
    sys.exit(main())
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/bin/pants_loader.py", line 94, in main
    PantsLoader.run()
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/bin/pants_loader.py", line 90, in run
    cls.load_and_execute(entrypoint)
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/bin/pants_loader.py", line 83, in load_and_execute
    entrypoint_main()
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/bin/pants_exe.py", line 32, in main
    PantsRunner(start_time=start_time).run()
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/bin/pants_runner.py", line 115, in run
    return runner.run()
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/bin/local_pants_runner.py", line 293, in run
    self._run()
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/bin/local_pants_runner.py", line 389, in _run
    goal_runner_result = self._maybe_run_v1()
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/bin/local_pants_runner.py", line 330, in _maybe_run_v1
    self._exiter,
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/bin/goal_runner.py", line 230, in run
    return self._run_goals()
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/bin/goal_runner.py", line 201, in _run_goals
    result = self._execute_engine()
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/bin/goal_runner.py", line 189, in _execute_engine
    result = engine.execute(self._context, self._goals)
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/engine/legacy_engine.py", line 21, in execute
    self.attempt(context, goals)
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/engine/round_engine.py", line 252, in attempt
    goal_executor.attempt(explain)
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/engine/round_engine.py", line 50, in attempt
    task.execute()
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/backend/python/tasks/resolve_requirements.py", line 29, in execute
    pex = self.resolve_requirements(interpreter, self.context.targets(has_python_requirements))
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/backend/python/tasks/resolve_requirements_task_base.py", line 96, in resolve_requirements
    pex_builder.add_requirement_libs_from(req_libs, platforms=platforms)
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/python/pex_build_util.py", line 202, in add_requirement_libs_from
    self.add_resolved_requirements(reqs, platforms=platforms)
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/python/pex_build_util.py", line 275, in add_resolved_requirements
    distributions = self.resolve_distributions(reqs, platforms=platforms)
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/python/pex_build_util.py", line 251, in resolve_distributions
    self._builder.interpreter, list(deduped_reqs), platforms, list(find_links),
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pants/python/pex_build_util.py", line 339, in _resolve_multi
    manylinux=python_setup.manylinux,
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pex/resolver.py", line 722, in resolve
    return list(resolve_request.resolve_distributions(ignore_errors=ignore_errors))
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pex/resolver.py", line 521, in resolve_distributions
    raise_type=Unsatisfiable):
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pex/resolver.py", line 392, in _run_parallel
    max_jobs=self._max_parallel_jobs
  File "/home/cedriczheng/.cache/pants/setup/bootstrap-Linux-x86_64/1.26.0_py37/lib/python3.7/site-packages/pex/jobs.py", line 219, in execute_parallel
    raise error

Looks like a python2 syntax error again, though I have no idea how to fix this. Thanks!

Looks like you've hit this bug in the underlying pip: https://github.com/pypa/setuptools/issues/1694#issuecomment-466010982

hmm I think that’s the result of

-ldebug

Huh. Do you expect Python two or Python three to be used?

There are a few scripts in my

bin

that use

compatibility='CPython>=3.5'

Your codebase is 2.7 right?

oh I see. I ran two different

./pants binary … -ldebug --print-exception-stacktrace

And can you post your full

pants.ini

?

There are something like this in BUILD:

python_requirement_library(
    name='ruamel_0_16_10',
    requirements=[
        python_requirement(
            name='ruamel.yaml',
            requirement='ruamel.yaml==0.16.10',
            compatibility='CPython>=3.5'),
    ],
)

Are these the reason that I need python>=3.5?

I would guess so. If your code requires Python 2.7 then I don't see how that requirement can work for you?