setuptools - ValueError: Newlines are not allowed

[michael-lazar]

Greetings!

It looks like with the newest release of setuptools this package is now failing to install. The issue is that there's a newline in the package description which is no longer permitted by setuptools.

pypa/setuptools#1390

https://github.com/venmo/business-rules/blob/master/setup.py#L15

python3.8 -m pip show setuptools
Name: setuptools
Version: 59.0.1
Summary: Easily download, build, install, upgrade, and uninstall Python packages
Home-page: https://github.com/pypa/setuptools
Author: Python Packaging Authority
Author-email: distutils-sig@python.org
License: UNKNOWN
Location: /usr/local/lib/python3.8/site-packages
Requires:
Required-by: check-manifest

python3.8 -m pip install business-rules==1.0.1
Collecting business-rules==1.0.1
  Using cached business-rules-1.0.1.tar.gz (13 kB)
    ERROR: Command errored out with exit status 1:
     command: /usr/local/opt/python@3.8/bin/python3.8 -c 'import io, os, sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/qm/qnlxs5yj14vf2x5k94vrd10m0000gn/T/pip-install-05q8s9vi/business-rules_19d9ce7311f243dc8d21bd4d97ec02d0/setup.py'"'"'; __file__='"'"'/private/var/folders/qm/qnlxs5yj14vf2x5k94vrd10m0000gn/T/pip-install-05q8s9vi/business-rules_19d9ce7311f243dc8d21bd4d97ec02d0/setup.py'"'"';f = getattr(tokenize, '"'"'open'"'"', open)(__file__) if os.path.exists(__file__) else io.StringIO('"'"'from setuptools import setup; setup()'"'"');code = f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /private/var/folders/qm/qnlxs5yj14vf2x5k94vrd10m0000gn/T/pip-pip-egg-info-68fyu19n
         cwd: /private/var/folders/qm/qnlxs5yj14vf2x5k94vrd10m0000gn/T/pip-install-05q8s9vi/business-rules_19d9ce7311f243dc8d21bd4d97ec02d0/
    Complete output (26 lines):
    running egg_info
    creating /private/var/folders/qm/qnlxs5yj14vf2x5k94vrd10m0000gn/T/pip-pip-egg-info-68fyu19n/business_rules.egg-info
    writing /private/var/folders/qm/qnlxs5yj14vf2x5k94vrd10m0000gn/T/pip-pip-egg-info-68fyu19n/business_rules.egg-info/PKG-INFO
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/var/folders/qm/qnlxs5yj14vf2x5k94vrd10m0000gn/T/pip-install-05q8s9vi/business-rules_19d9ce7311f243dc8d21bd4d97ec02d0/setup.py", line 12, in <module>
        setuptools.setup(
      File "/usr/local/lib/python3.8/site-packages/setuptools/__init__.py", line 159, in setup
        return distutils.core.setup(**attrs)
      File "/usr/local/Cellar/python@3.8/3.8.11/Frameworks/Python.framework/Versions/3.8/lib/python3.8/distutils/core.py", line 148, in setup
        dist.run_commands()
      File "/usr/local/Cellar/python@3.8/3.8.11/Frameworks/Python.framework/Versions/3.8/lib/python3.8/distutils/dist.py", line 966, in run_commands
        self.run_command(cmd)
      File "/usr/local/Cellar/python@3.8/3.8.11/Frameworks/Python.framework/Versions/3.8/lib/python3.8/distutils/dist.py", line 985, in run_command
        cmd_obj.run()
      File "/usr/local/lib/python3.8/site-packages/setuptools/command/egg_info.py", line 292, in run
        writer(self, ep.name, os.path.join(self.egg_info, ep.name))
      File "/usr/local/lib/python3.8/site-packages/setuptools/command/egg_info.py", line 656, in write_pkg_info
        metadata.write_pkg_info(cmd.egg_info)
      File "/usr/local/Cellar/python@3.8/3.8.11/Frameworks/Python.framework/Versions/3.8/lib/python3.8/distutils/dist.py", line 1117, in write_pkg_info
        self.write_pkg_file(pkg_info)
      File "/usr/local/lib/python3.8/site-packages/setuptools/dist.py", line 167, in write_pkg_file
        write_field('Summary', single_line(self.get_description()))
      File "/usr/local/lib/python3.8/site-packages/setuptools/dist.py", line 151, in single_line
        raise ValueError('Newlines are not allowed')
    ValueError: Newlines are not allowed
    ----------------------------------------
WARNING: Discarding https://files.pythonhosted.org/packages/44/b1/5aa6d81111e701e83917ee4b16ac8882c2c4dfde57af4013f1f97a2175ac/business-rules-1.0.1.tar.gz#sha256=e0f58104df937378856e8199a49af4f5b4dbe5ac21b863a080810dedc3326d1d (from https://pypi.org/simple/business-rules/). Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
ERROR: Could not find a version that satisfies the requirement business-rules==1.0.1 (from versions: 0.1, 0.1.1, 0.1.2, 0.1.3, 0.2.0, 1.0.1)
ERROR: No matching distribution found for business-rules==1.0.1

The issue can be worked around by downgrading to setuptools==58.5.3.

[MiguelSmith]

Yep, was about to create the issue myself. Can confirm that this is the source of the issue as well as the fix.

[mblayman]

With the revert from setuptools (pypa/setuptools#2893), this package is safe to install again. I do think it would be valuable to merge #68 still.