Cannot build on Python 3.8 because the version of psycopg2 is old

[niyalist]

Whth python 3.8, I found an error while building GTFSDB with zc.buildout. I think this is du to incompatibility of psycopg2, so updated version.conf and now it works. I also found some warnings caused by zc.buildout, but it somehow works well.

Error:

$ buildout install prod postgresql
/usr/local/lib/python3.8/site-packages/setuptools/distutils_patch.py:25: UserWarning: Distutils was imported before Setuptools. This usage is discouraged and may exhibit undesirable behaviors or errors. Please use Setuptools' objects directly or at least import Setuptools first.
warnings.warn(
Creating directory '/Users/XXX/gtfsdb/eggs'.
Creating directory '/Users/XXX/gtfsdb/bin'.
Creating directory '/Users/XXX/gtfsdb/parts'.
Creating directory '/Users/XXX/gtfsdb/develop-eggs'.
Develop: '/Users/XXX/gtfsdb/.'
Warning: 'classifiers' should be a list, got type 'tuple'
Getting distribution for 'zc.recipe.egg==2.0.7'.
WARNING: The easy_install command is deprecated and will be removed in a future version.
Got zc.recipe.egg 2.0.7.
Unused options for buildout: 'allowed-eggs-from-site-packages' 'app-egg-name' 'include-site-packages'.
Installing prod.
Getting distribution for 'psycopg2==2.7.7'.
WARNING: The easy_install command is deprecated and will be removed in a future version.
psycopg/psycopgmodule.c:689:18: error: incomplete definition of type 'struct _is'
while (interp->next)
~~~~~~^
/usr/local/Cellar/python@3.8/3.8.5/Frameworks/Python.framework/Versions/3.8/include/python3.8/pystate.h:20:8: note: forward declaration of 'struct _is'
struct _is;
^
psycopg/psycopgmodule.c:690:24: error: incomplete definition of type 'struct _is'
interp = interp->next;
~~~~~~^
/usr/local/Cellar/python@3.8/3.8.5/Frameworks/Python.framework/Versions/3.8/include/python3.8/pystate.h:20:8: note: forward declaration of 'struct _is'
struct _is;
^
2 errors generated.

It appears you are missing some prerequisite to build the package from source.

You may install a binary package by installing 'psycopg2-binary' from PyPI.
If you want to install psycopg2 from source, please install the packages
required for the build and try again.

For further information please check the 'doc/src/install.rst' file (also at
http://initd.org/psycopg/docs/install.html).

error: Setup script exited with error: command 'clang' failed with exit status 1
An error occurred when trying to install /var/folders/b9/lqn5qty9425_wnngw1bz2n2r0000gn/T/tmp9xbfppb2get_dist/psycopg2-2.7.7.tar.gz. Look above this message for any errors that were output by easy_install.
While:
Installing prod.
Getting distribution for 'psycopg2==2.7.7'.

An internal error occurred due to a bug in either zc.buildout or in a
recipe being used:
Traceback (most recent call last):
File "/usr/local/lib/python3.8/site-packages/zc/buildout/buildout.py", line 2174, in main
getattr(buildout, command)(args)
File "/usr/local/lib/python3.8/site-packages/zc/buildout/buildout.py", line 817, in install
installed_files = self[part]._call(recipe.install)
File "/usr/local/lib/python3.8/site-packages/zc/buildout/buildout.py", line 1603, in _call
return f()
File "/Users/XXX/gtfsdb/eggs/zc.recipe.egg-2.0.7-py3.8.egg/zc/recipe/egg/egg.py", line 227, in install
reqs, ws = self.working_set()
File "/Users/XXX/gtfsdb/eggs/zc.recipe.egg-2.0.7-py3.8.egg/zc/recipe/egg/egg.py", line 78, in working_set
ws = self._working_set(
File "/Users/XXX/gtfsdb/eggs/zc.recipe.egg-2.0.7-py3.8.egg/zc/recipe/egg/egg.py", line 161, in _working_set
ws = zc.buildout.easy_install.install(
File "/usr/local/lib/python3.8/site-packages/zc/buildout/easy_install.py", line 957, in install
return installer.install(specs, working_set)
File "/usr/local/lib/python3.8/site-packages/zc/buildout/easy_install.py", line 730, in install
for dist in self._get_dist(req, ws):
File "/usr/local/lib/python3.8/site-packages/zc/buildout/easy_install.py", line 574, in _get_dist
dists = [_move_to_eggs_dir_and_compile(dist, self._dest)]
File "/usr/local/lib/python3.8/site-packages/zc/buildout/easy_install.py", line 1745, in _move_to_eggs_dir_and_compile
[tmp_loc] = glob.glob(os.path.join(tmp_dest, '*'))
ValueError: not enough values to unpack (expected 1, got 0)
$

Quick Fix:
Fix "psycopg2 = 2.7.7" in versions.cfg into psycopg2 = 2.8.5

Environment:
macOS Catalina 10.15.6
Homebrew 2.4.13-97-g1b4e1ae
Python 3.8.5
zc.buildout 2.13.3

[fpurcell]

Thanks @niyalist ... will take a look and let you know here.

BTW, versions.cfg is auto generated ... I check it in, in hopes of making for a repeatable build. I'll try updating psycopg2 and testing on a few versions of python, and will then commit an updated versions.cfg if there are no issues.

Current workaround for py 3.8: edit versions.cfg and remove pinned psycopg2.