Startup fails with Sentry configured and setuptools 20.2+

[gi11es]

vagrant@mediawiki-vagrant:~$ sudo -u thumbor /srv/thumbor/bin/python /srv/thumbor/bin/thumbor -c /etc/thumbor.conf -a tc_core.app.App
2016-03-10 08:08:36 sentry.errors.serializer:ERROR 'Requirement' object has no attribute 'name'
Traceback (most recent call last):
  File "/srv/thumbor/local/lib/python2.7/site-packages/raven/utils/serializer/manager.py", line 76, in transform
    return repr(value)
  File "/srv/thumbor/local/lib/python2.7/site-packages/pkg_resources/_vendor/packaging/requirements.py", line 127, in __repr__
    return "<Requirement({0!r})>".format(str(self))
  File "/srv/thumbor/local/lib/python2.7/site-packages/pkg_resources/_vendor/packaging/requirements.py", line 110, in __str__
    parts = [self.name]
AttributeError: 'Requirement' object has no attribute 'name'
Traceback (most recent call last):
  File "/srv/thumbor/bin/thumbor", line 9, in <module>
    load_entry_point('thumbor==5.2.1', 'console_scripts', 'thumbor')()
  File "/srv/thumbor/local/lib/python2.7/site-packages/thumbor/server.py", line 124, in main
    importer = get_importer(config)
  File "/srv/thumbor/local/lib/python2.7/site-packages/thumbor/server.py", line 61, in get_importer
    importer.error_handler = importer.error_handler_class(config)
  File "/srv/thumbor/local/lib/python2.7/site-packages/thumbor/error_handlers/sentry.py", line 29, in __init__
    self.modules = self.get_modules()
  File "/srv/thumbor/local/lib/python2.7/site-packages/thumbor/error_handlers/sentry.py", line 36, in get_modules
    res_mod = pkg_resources.get_distribution(module)
  File "/srv/thumbor/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 540, in get_distribution
    dist = Requirement.parse(dist)
  File "/srv/thumbor/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2818, in parse
    req, = parse_requirements(s)
  File "/srv/thumbor/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2762, in parse_requirements
    req = packaging.requirements.Requirement(line)
  File "/srv/thumbor/local/lib/python2.7/site-packages/pkg_resources/_vendor/packaging/requirements.py", line 94, in __init__
    requirement_string[e.loc:e.loc + 8]))
pkg_resources._vendor.packaging.requirements.InvalidRequirement: Invalid requirement, parse error at "'_abcoll'"