Needs to handle VersionConflict in consider_setuptools_entrypoints

[pytestbot]

Originally reported by: Daniel Hahler (BitBucket: blueyed, GitHub: blueyed)

---

I was getting the following error, caused by the testmon plugin, which
requires pytest<2.7:

…/pyenv/project2/lib/python2.7/site-packages/_pytest/config.py in _preparse(self, args, addopts)
    711         self._checkversion()
    712         self.pluginmanager.consider_preparse(args)
--> 713         self.pluginmanager.consider_setuptools_entrypoints()
    714         self.pluginmanager.consider_env()
    715         self.known_args_namespace = ns = self._parser.parse_known_args(args)

…/pyenv/project2/lib/python2.7/site-packages/_pytest/core.py in consider_setuptools_entrypoints(self)
    276                 continue
    277             try:
--> 278                 plugin = ep.load()
    279             except DistributionNotFound:
    280                 continue

…/pyenv/project2/lib/python2.7/site-packages/pkg_resources/__init__.py in load(self, require, *args, **kwargs)
   2318             )
   2319         if require:
-> 2320             self.require(*args, **kwargs)
   2321         return self.resolve()
   2322 

…/pyenv/project2/lib/python2.7/site-packages/pkg_resources/__init__.py in require(self, env, installer)
   2335             raise UnknownExtra("Can't require() without a distribution", self)
   2336         reqs = self.dist.requires(self.extras)
-> 2337         items = working_set.resolve(reqs, env, installer)
   2338         list(map(working_set.add, items))
   2339 

…/pyenv/project2/lib/python2.7/site-packages/pkg_resources/__init__.py in resolve(self, requirements, env, installer, replace_conflicting)
    812                 dependent_req = required_by[req]
    813                 import ipdb; ipdb.set_trace()  # noqa
--> 814                 raise VersionConflict(dist, req).with_context(dependent_req)
    815 
    816             # push the new requirements onto the stack

VersionConflict: (pytest 2.7.0 (…/pyenv/project2/lib/python2.7/site-packages), Requirement.parse('pytest<2.7'))


ipdb> args
self = <pkg_resources.WorkingSet object at 0x7f3ec2a55cd0>
requirements = [Requirement.parse('pathtools>=0.1.1'), Requirement.parse('argh>=0.24.1'), Requirement.parse('PyYAML>=3.10'), Requirement.parse('execnet>=1.1.dev1'), Requ
irement.parse('pytest>=2.2')]                                                                                                                                            env = None
installer = None
replace_conflicting = False

ep is EntryPoint.parse('testmon = testmon.plugin').

It would be nice if there was a warning in such a case and the plugin was
skipped.

A warning might be useful with the current handling of DistributionNotFound,
too.

---

• Bitbucket: https://bitbucket.org/pytest-dev/pytest/issue/704

[RonnyPfannschmidt]

this is now in pluggy, @hpk42 @flub - is this a candidate for a person at the sprint?

[flub]

Yes, sure
On 25 Jul 2015 11:50, "Ronny Pfannschmidt" notifications@github.com wrote:

this is now in pluggy, @hpk42 https://github.com/hpk42 @flub
https://github.com/flub - is this a candidate for a person at the
sprint?

—
Reply to this email directly or view it on GitHub
#704 (comment).

[nicoddemus]

Is this still an issue?

[RonnyPfannschmidt]

I think pluggy has a better handling now, wed need to vendor and test

[blueyed]

Still not better:

Traceback (most recent call last):
  File "…/pyenv/project/bin/py.test", line 9, in <module>
    load_entry_point('pytest', 'console_scripts', 'py.test')()
  File "…/pytest/_pytest/config.py", line 39, in main
    config = _prepareconfig(args, plugins)
  File "…/pytest/_pytest/config.py", line 118, in _prepareconfig
    pluginmanager=pluginmanager, args=args)
  File "…/pytest/_pytest/vendored_packages/pluggy.py", line 724, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "…/pytest/_pytest/vendored_packages/pluggy.py", line 338, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "…/pytest/_pytest/vendored_packages/pluggy.py", line 333, in <lambda>
    _MultiCall(methods, kwargs, hook.spec_opts).execute()
  File "…/pytest/_pytest/vendored_packages/pluggy.py", line 595, in execute
    return _wrapped_call(hook_impl.function(*args), self.execute)
  File "…/pytest/_pytest/vendored_packages/pluggy.py", line 249, in _wrapped_call
    wrap_controller.send(call_outcome)
  File "…/pytest/_pytest/helpconfig.py", line 28, in pytest_cmdline_parse
    config = outcome.get_result()
  File "…/pytest/_pytest/vendored_packages/pluggy.py", line 278, in get_result
    raise ex[1].with_traceback(ex[2])
  File "…/pytest/_pytest/vendored_packages/pluggy.py", line 264, in __init__
    self.result = func()
  File "…/pytest/_pytest/vendored_packages/pluggy.py", line 596, in execute
    res = hook_impl.function(*args)
  File "…/pytest/_pytest/config.py", line 856, in pytest_cmdline_parse
    self.parse(args)
  File "…/pytest/_pytest/config.py", line 961, in parse
    self._preparse(args, addopts=addopts)
  File "…/pytest/_pytest/config.py", line 922, in _preparse
    self.pluginmanager.load_setuptools_entrypoints("pytest11")
  File "…/pytest/_pytest/vendored_packages/pluggy.py", line 501, in load_setuptools_entrypoints
    plugin = ep.load()
  File "…/pyenv/project/lib/python3.5/site-packages/pkg_resources/__init__.py", line 2379, in load
    self.require(*args, **kwargs)
  File "…/pyenv/project/lib/python3.5/site-packages/pkg_resources/__init__.py", line 2396, in require
    items = working_set.resolve(reqs, env, installer)
  File "…/pyenv/project/lib/python3.5/site-packages/pkg_resources/__init__.py", line 854, in resolve
    raise VersionConflict(dist, req).with_context(dependent_req)
pkg_resources.VersionConflict: (pytest 2.9.1.dev1 (…/pytest), Requirement.parse('pytest<2.9,>=2.7.0'))

This happened with an older pytest-testmon package, after only updating pytest.

Where is the upstream source for pluggy hosted?

A patch could look like this, but should also display the error / problem (mentioning also ep/ep.name):

diff --git i/_pytest/vendored_packages/pluggy.py w/_pytest/vendored_packages/pluggy.
index 2f848b2..3ed558b 100644
--- i/_pytest/vendored_packages/pluggy.py
+++ w/_pytest/vendored_packages/pluggy.py
@@ -492,7 +492,8 @@ def check_pending(self):
     def load_setuptools_entrypoints(self, entrypoint_name):
         """ Load modules from querying the specified setuptools entrypoint name.
         Return the number of loaded plugins. """
-        from pkg_resources import iter_entry_points, DistributionNotFound
+        from pkg_resources import (iter_entry_points, DistributionNotFound,
+                                   VersionConflict)
         for ep in iter_entry_points(entrypoint_name):
             # is the plugin registered or blocked?
             if self.get_plugin(ep.name) or self.is_blocked(ep.name):
@@ -501,6 +502,8 @@ def load_setuptools_entrypoints(self, entrypoint_name):
                 plugin = ep.load()
             except DistributionNotFound:
                 continue
+            except VersionConflict as excinfo:
+                continue
             self.register(plugin, name=ep.name)
             self._plugin_distinfo.append((plugin, ep.dist))
         return len(self._plugin_distinfo)

[The-Compiler]

Where is the upstream source for pluggy hosted?

https://github.com/hpk42/pluggy

[blueyed]

Thanks, it was fixed in pytest-dev/pluggy#8.

[blueyed]

But 0.3.2 is not released and vendored yet.
Not sure if this issue for pytest should get re-opened.
A new release of pluggy seems to be a good idea for the (end of the) sprint?! https://github.com/hpk42/pluggy/blob/master/CHANGELOG

[nicoddemus]

That's a good idea @blueyed, created an issue for it