prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  Upstream change in django-treebeard 4.5 requires a new wagtail core migration
  Default MP_Node depth has changed to 1.
  
  https://github.com/django-treebeard/django-treebeard/commit/454be8f29ac2b4b4fbe6512357b5afc1eb422bab#diff-35501ef525349cd39e4713d1a9f64a249fa4fbd31d875513e3a15e65988701a2
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `setup.py`
  Content:
  ```
  1 #!/usr/bin/env python
  2 
  3 from wagtail import __version__
  4 from wagtail.utils.setup import assets, check_bdist_egg, sdist
  5 
  6 
  7 try:
  8     from setuptools import find_packages, setup
  9 except ImportError:
  10     from distutils.core import setup
  11 
  12 
  13 # Hack to prevent "TypeError: 'NoneType' object is not callable" error
  14 # in multiprocessing/util.py _exit_function when setup.py exits
  15 # (see http://www.eby-sarna.com/pipermail/peak/2010-May/003357.html)
  16 try:
  17     import multiprocessing  # noqa
  18 except ImportError:
  19     pass
  20 
  21 
  22 install_requires = [
  23     "Django>=2.2,<3.2",
  24     "django-modelcluster>=5.1,<6.0",
  25     "django-taggit>=1.0,<2.0",
  26     "django-treebeard>=4.2.0,<4.5",
  27     "djangorestframework>=3.11.1,<4.0",
  28     "django-filter>=2.2,<3.0",
  29     "draftjs_exporter>=2.1.5,<3.0",
  30     "Pillow>=4.0.0,<9.0.0",
  31     "beautifulsoup4>=4.8,<4.9",
  32     "html5lib>=0.999,<2",
  33     "Willow>=1.4,<1.5",
  34     "requests>=2.11.1,<3.0",
  35     "l18n>=2018.5",
  36     "xlsxwriter>=1.2.8,<2.0",
  37     "tablib[xls,xlsx]>=0.14.0",
  38     "anyascii>=0.1.5",
  39 ]
  40 
  41 # Testing dependencies
  42 testing_extras = [
  43     # Required for running the tests
  44     'python-dateutil>=2.2',
  45     'pytz>=2014.7',
  46     'elasticsearch>=5.0,<6.0',
  47     'Jinja2>=2.11,<3.0',
  48     'boto3>=1.16,<1.17',
  49     'freezegun>=0.3.8',
  50     'openpyxl>=2.6.4',
  51     'Unidecode>=0.04.14,<2.0',
  52 
  53     # For coverage and PEP8 linting
  54     'coverage>=3.7.0',
  55     'flake8>=3.6.0',
  56     'isort==5.6.4',  # leave this pinned - it tends to change rules between patch releases
  57     'flake8-blind-except==0.1.1',
  58     'flake8-print==2.0.2',
  59     'doc8==0.8.1',
  60 
  61     # For templates linting
  62     'jinjalint>=0.5',
  63 
  64     # Pipenv hack to fix broken dependency causing CircleCI failures
  65     'docutils==0.15',
  66 
  67     # django-taggit 1.3.0 made changes to verbose_name which affect migrations;
  68     # the test suite migrations correspond to >=1.3.0
  69     'django-taggit>=1.3.0,<2.0',
  70 ]
  71 
  72 # Documentation dependencies
  73 documentation_extras = [
  74     'pyenchant>=3.1.1,<4',
  75     'sphinxcontrib-spelling>=5.4.0,<6',
  76     'Sphinx>=1.5.2',
  77     'sphinx-autobuild>=0.6.0',
  78     'sphinx_rtd_theme>=0.1.9',
  79     'recommonmark>=0.7.1',
  80 ]
  81 
  82 setup(
  83     name='wagtail',
  84     version=__version__,
  85     description='A Django content management system.',
  86     author='Wagtail core team + contributors',
  87     author_email='hello@wagtail.io',  # For support queries, please see https://docs.wagtail.io/en/stable/support.html
  88     url='https://wagtail.io/',
  89     packages=find_packages(),
  90     include_package_data=True,
  91     license='BSD',
  92     long_description="Wagtail is an open source content management \
  93 system built on Django, with a strong community and commercial support. \
  94 It’s focused on user experience, and offers precise control for \
  95 designers and developers.\n\n\
  96 For more details, see https://wagtail.io, https://docs.wagtail.io and \
  97 https://github.com/wagtail/wagtail/.",
  98     classifiers=[
  99         'Development Status :: 5 - Production/Stable',
  100         'Environment :: Web Environment',
  101         'Intended Audience :: Developers',
  102         'License :: OSI Approved :: BSD License',
  103         'Operating System :: OS Independent',
  104         'Programming Language :: Python',
  105         'Programming Language :: Python :: 3',
  106         'Programming Language :: Python :: 3.6',
  107         'Programming Language :: Python :: 3.7',
  108         'Programming Language :: Python :: 3.8',
  109         'Programming Language :: Python :: 3.9',
  110         'Framework :: Django',
  111         'Framework :: Django :: 2.2',
  112         'Framework :: Django :: 3.0',
  113         'Framework :: Django :: 3.1',
  114         'Framework :: Wagtail',
  115         'Topic :: Internet :: WWW/HTTP :: Site Management',
  116     ],
  117     python_requires='>=3.6',
  118     install_requires=install_requires,
  119     extras_require={
  120         'testing': testing_extras,
  121         'docs': documentation_extras
  122     },
  123     entry_points="""
  124             [console_scripts]
  125             wagtail=wagtail.bin.wagtail:main
  126     """,
  127     zip_safe=False,
  128     cmdclass={
  129         'sdist': sdist,
  130         'bdist_egg': check_bdist_egg,
  131         'assets': assets,
  132     },
  133 )
  134
  ```
  --- END FILES ---
  
  Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.
  
  Here is an example:
  
  ```diff
  diff --git a/examples/server_async.py b/examples/server_async.py
  --- a/examples/server_async.py
  +++ b/examples/server_async.py
  @@ -313,4 +313,4 @@
   
   
   if __name__ == "__main__":
  -    asyncio.run(run_async_server("."), debug=True)
  +    asyncio.run(run_async_server(), debug=True)
  diff --git a/examples/server_sync.py b/examples/server_sync.py
  --- a/examples/server_sync.py
  +++ b/examples/server_sync.py
  @@ -313,5 +313,5 @@
   
   
   if __name__ == "__main__":
  -    server = run_sync_server(".")
  +    server = run_sync_server()
       server.shutdown()
  
  ```
  
golden_diff: diff --git a/setup.py b/setup.py
  --- a/setup.py
  +++ b/setup.py
  @@ -23,7 +23,7 @@
       "Django>=2.2,<3.2",
       "django-modelcluster>=5.1,<6.0",
       "django-taggit>=1.0,<2.0",
  -    "django-treebeard>=4.2.0,<4.5",
  +    "django-treebeard>=4.2.0,<5.0,!=4.5",
       "djangorestframework>=3.11.1,<4.0",
       "django-filter>=2.2,<3.0",
       "draftjs_exporter>=2.1.5,<3.0",
  
verification_info: {"golden_diff": "diff --git a/setup.py b/setup.py\n--- a/setup.py\n+++ b/setup.py\n@@ -23,7 +23,7 @@\n     \"Django>=2.2,<3.2\",\n     \"django-modelcluster>=5.1,<6.0\",\n     \"django-taggit>=1.0,<2.0\",\n-    \"django-treebeard>=4.2.0,<4.5\",\n+    \"django-treebeard>=4.2.0,<5.0,!=4.5\",\n     \"djangorestframework>=3.11.1,<4.0\",\n     \"django-filter>=2.2,<3.0\",\n     \"draftjs_exporter>=2.1.5,<3.0\",\n", "issue": "Upstream change in django-treebeard 4.5 requires a new wagtail core migration\nDefault MP_Node depth has changed to 1.\r\n\r\nhttps://github.com/django-treebeard/django-treebeard/commit/454be8f29ac2b4b4fbe6512357b5afc1eb422bab#diff-35501ef525349cd39e4713d1a9f64a249fa4fbd31d875513e3a15e65988701a2\n", "before_files": [{"content": "#!/usr/bin/env python\n\nfrom wagtail import __version__\nfrom wagtail.utils.setup import assets, check_bdist_egg, sdist\n\n\ntry:\n    from setuptools import find_packages, setup\nexcept ImportError:\n    from distutils.core import setup\n\n\n# Hack to prevent \"TypeError: 'NoneType' object is not callable\" error\n# in multiprocessing/util.py _exit_function when setup.py exits\n# (see http://www.eby-sarna.com/pipermail/peak/2010-May/003357.html)\ntry:\n    import multiprocessing  # noqa\nexcept ImportError:\n    pass\n\n\ninstall_requires = [\n    \"Django>=2.2,<3.2\",\n    \"django-modelcluster>=5.1,<6.0\",\n    \"django-taggit>=1.0,<2.0\",\n    \"django-treebeard>=4.2.0,<4.5\",\n    \"djangorestframework>=3.11.1,<4.0\",\n    \"django-filter>=2.2,<3.0\",\n    \"draftjs_exporter>=2.1.5,<3.0\",\n    \"Pillow>=4.0.0,<9.0.0\",\n    \"beautifulsoup4>=4.8,<4.9\",\n    \"html5lib>=0.999,<2\",\n    \"Willow>=1.4,<1.5\",\n    \"requests>=2.11.1,<3.0\",\n    \"l18n>=2018.5\",\n    \"xlsxwriter>=1.2.8,<2.0\",\n    \"tablib[xls,xlsx]>=0.14.0\",\n    \"anyascii>=0.1.5\",\n]\n\n# Testing dependencies\ntesting_extras = [\n    # Required for running the tests\n    'python-dateutil>=2.2',\n    'pytz>=2014.7',\n    'elasticsearch>=5.0,<6.0',\n    'Jinja2>=2.11,<3.0',\n    'boto3>=1.16,<1.17',\n    'freezegun>=0.3.8',\n    'openpyxl>=2.6.4',\n    'Unidecode>=0.04.14,<2.0',\n\n    # For coverage and PEP8 linting\n    'coverage>=3.7.0',\n    'flake8>=3.6.0',\n    'isort==5.6.4',  # leave this pinned - it tends to change rules between patch releases\n    'flake8-blind-except==0.1.1',\n    'flake8-print==2.0.2',\n    'doc8==0.8.1',\n\n    # For templates linting\n    'jinjalint>=0.5',\n\n    # Pipenv hack to fix broken dependency causing CircleCI failures\n    'docutils==0.15',\n\n    # django-taggit 1.3.0 made changes to verbose_name which affect migrations;\n    # the test suite migrations correspond to >=1.3.0\n    'django-taggit>=1.3.0,<2.0',\n]\n\n# Documentation dependencies\ndocumentation_extras = [\n    'pyenchant>=3.1.1,<4',\n    'sphinxcontrib-spelling>=5.4.0,<6',\n    'Sphinx>=1.5.2',\n    'sphinx-autobuild>=0.6.0',\n    'sphinx_rtd_theme>=0.1.9',\n    'recommonmark>=0.7.1',\n]\n\nsetup(\n    name='wagtail',\n    version=__version__,\n    description='A Django content management system.',\n    author='Wagtail core team + contributors',\n    author_email='hello@wagtail.io',  # For support queries, please see https://docs.wagtail.io/en/stable/support.html\n    url='https://wagtail.io/',\n    packages=find_packages(),\n    include_package_data=True,\n    license='BSD',\n    long_description=\"Wagtail is an open source content management \\\nsystem built on Django, with a strong community and commercial support. \\\nIt\u2019s focused on user experience, and offers precise control for \\\ndesigners and developers.\\n\\n\\\nFor more details, see https://wagtail.io, https://docs.wagtail.io and \\\nhttps://github.com/wagtail/wagtail/.\",\n    classifiers=[\n        'Development Status :: 5 - Production/Stable',\n        'Environment :: Web Environment',\n        'Intended Audience :: Developers',\n        'License :: OSI Approved :: BSD License',\n        'Operating System :: OS Independent',\n        'Programming Language :: Python',\n        'Programming Language :: Python :: 3',\n        'Programming Language :: Python :: 3.6',\n        'Programming Language :: Python :: 3.7',\n        'Programming Language :: Python :: 3.8',\n        'Programming Language :: Python :: 3.9',\n        'Framework :: Django',\n        'Framework :: Django :: 2.2',\n        'Framework :: Django :: 3.0',\n        'Framework :: Django :: 3.1',\n        'Framework :: Wagtail',\n        'Topic :: Internet :: WWW/HTTP :: Site Management',\n    ],\n    python_requires='>=3.6',\n    install_requires=install_requires,\n    extras_require={\n        'testing': testing_extras,\n        'docs': documentation_extras\n    },\n    entry_points=\"\"\"\n            [console_scripts]\n            wagtail=wagtail.bin.wagtail:main\n    \"\"\",\n    zip_safe=False,\n    cmdclass={\n        'sdist': sdist,\n        'bdist_egg': check_bdist_egg,\n        'assets': assets,\n    },\n)\n", "path": "setup.py"}], "after_files": [{"content": "#!/usr/bin/env python\n\nfrom wagtail import __version__\nfrom wagtail.utils.setup import assets, check_bdist_egg, sdist\n\n\ntry:\n    from setuptools import find_packages, setup\nexcept ImportError:\n    from distutils.core import setup\n\n\n# Hack to prevent \"TypeError: 'NoneType' object is not callable\" error\n# in multiprocessing/util.py _exit_function when setup.py exits\n# (see http://www.eby-sarna.com/pipermail/peak/2010-May/003357.html)\ntry:\n    import multiprocessing  # noqa\nexcept ImportError:\n    pass\n\n\ninstall_requires = [\n    \"Django>=2.2,<3.2\",\n    \"django-modelcluster>=5.1,<6.0\",\n    \"django-taggit>=1.0,<2.0\",\n    \"django-treebeard>=4.2.0,<5.0,!=4.5\",\n    \"djangorestframework>=3.11.1,<4.0\",\n    \"django-filter>=2.2,<3.0\",\n    \"draftjs_exporter>=2.1.5,<3.0\",\n    \"Pillow>=4.0.0,<9.0.0\",\n    \"beautifulsoup4>=4.8,<4.9\",\n    \"html5lib>=0.999,<2\",\n    \"Willow>=1.4,<1.5\",\n    \"requests>=2.11.1,<3.0\",\n    \"l18n>=2018.5\",\n    \"xlsxwriter>=1.2.8,<2.0\",\n    \"tablib[xls,xlsx]>=0.14.0\",\n    \"anyascii>=0.1.5\",\n]\n\n# Testing dependencies\ntesting_extras = [\n    # Required for running the tests\n    'python-dateutil>=2.2',\n    'pytz>=2014.7',\n    'elasticsearch>=5.0,<6.0',\n    'Jinja2>=2.11,<3.0',\n    'boto3>=1.16,<1.17',\n    'freezegun>=0.3.8',\n    'openpyxl>=2.6.4',\n    'Unidecode>=0.04.14,<2.0',\n\n    # For coverage and PEP8 linting\n    'coverage>=3.7.0',\n    'flake8>=3.6.0',\n    'isort==5.6.4',  # leave this pinned - it tends to change rules between patch releases\n    'flake8-blind-except==0.1.1',\n    'flake8-print==2.0.2',\n    'doc8==0.8.1',\n\n    # For templates linting\n    'jinjalint>=0.5',\n\n    # Pipenv hack to fix broken dependency causing CircleCI failures\n    'docutils==0.15',\n\n    # django-taggit 1.3.0 made changes to verbose_name which affect migrations;\n    # the test suite migrations correspond to >=1.3.0\n    'django-taggit>=1.3.0,<2.0',\n]\n\n# Documentation dependencies\ndocumentation_extras = [\n    'pyenchant>=3.1.1,<4',\n    'sphinxcontrib-spelling>=5.4.0,<6',\n    'Sphinx>=1.5.2',\n    'sphinx-autobuild>=0.6.0',\n    'sphinx_rtd_theme>=0.1.9',\n    'recommonmark>=0.7.1',\n]\n\nsetup(\n    name='wagtail',\n    version=__version__,\n    description='A Django content management system.',\n    author='Wagtail core team + contributors',\n    author_email='hello@wagtail.io',  # For support queries, please see https://docs.wagtail.io/en/stable/support.html\n    url='https://wagtail.io/',\n    packages=find_packages(),\n    include_package_data=True,\n    license='BSD',\n    long_description=\"Wagtail is an open source content management \\\nsystem built on Django, with a strong community and commercial support. \\\nIt\u2019s focused on user experience, and offers precise control for \\\ndesigners and developers.\\n\\n\\\nFor more details, see https://wagtail.io, https://docs.wagtail.io and \\\nhttps://github.com/wagtail/wagtail/.\",\n    classifiers=[\n        'Development Status :: 5 - Production/Stable',\n        'Environment :: Web Environment',\n        'Intended Audience :: Developers',\n        'License :: OSI Approved :: BSD License',\n        'Operating System :: OS Independent',\n        'Programming Language :: Python',\n        'Programming Language :: Python :: 3',\n        'Programming Language :: Python :: 3.6',\n        'Programming Language :: Python :: 3.7',\n        'Programming Language :: Python :: 3.8',\n        'Programming Language :: Python :: 3.9',\n        'Framework :: Django',\n        'Framework :: Django :: 2.2',\n        'Framework :: Django :: 3.0',\n        'Framework :: Django :: 3.1',\n        'Framework :: Wagtail',\n        'Topic :: Internet :: WWW/HTTP :: Site Management',\n    ],\n    python_requires='>=3.6',\n    install_requires=install_requires,\n    extras_require={\n        'testing': testing_extras,\n        'docs': documentation_extras\n    },\n    entry_points=\"\"\"\n            [console_scripts]\n            wagtail=wagtail.bin.wagtail:main\n    \"\"\",\n    zip_safe=False,\n    cmdclass={\n        'sdist': sdist,\n        'bdist_egg': check_bdist_egg,\n        'assets': assets,\n    },\n)\n", "path": "setup.py"}]}