Python bindings: Missing importlib_resources dependency

[tyilo]

The newest version of z3-solver on PyPI (v4.12.3.0) is requires the dependency importlib_resources, but it is not specified as a dependency.

Thus the z3 bindings for Python isn't working out of the box:

$ mkdir /tmp/z3-test
$ cd /tmp/z3-test
$ python -mvenv venv
$ venv/bin/pip install z3-solver
$ venv/bin/python -c 'import z3; print(z3)'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/tmp/z3-test/venv/lib/python3.11/site-packages/z3/__init__.py", line 1, in <module>
    from .z3 import *
  File "/tmp/z3-test/venv/lib/python3.11/site-packages/z3/z3.py", line 46, in <module>
    from . import z3core
  File "/tmp/z3-test/venv/lib/python3.11/site-packages/z3/z3core.py", line 7, in <module>
    import importlib_resources
ModuleNotFoundError: No module named 'importlib_resources'

Installing the importlib_resources dependency manually fixes the problem:

$ venv/bin/pip install importlib_resources
$ venv/bin/python -c 'import z3; print(z3)'
<module 'z3' from '/tmp/z3-test/venv/lib/python3.11/site-packages/z3/__init__.py'>

[NikolajBjorner]

Python 3.9 and up now use the built-in version thanks to #7042

[youchangkim]

@NikolajBjorner Is z3-4.12.3 only supporting python 3.9 and above? If so, we need python_requires so that old python versions don't pick up v4.12.3. If not, we need importlib_resources in install_requires to prevent ModuleNotFoundError on old python versions.

[NikolajBjorner]

what is the location to add install_requires?

[youchangkim]

If you use setup.py to build the wheels, you can add install_requires in the setup function.
https://setuptools.pypa.io/en/latest/userguide/dependency_management.html

[NikolajBjorner]

so pyproject.toml

[build-system]
requires = ["setuptools>=46.4.0", "wheel", "cmake"]
build-backend = "setuptools.build_meta"

becomes

[build-system]
requires = ["setuptools>=46.4.0", "wheel", "cmake", "importlib_resources"]
build-backend = "setuptools.build_meta"

?

[youchangkim]

I'm not super familiar with pyproject.toml, but it should go under [project].

[project]
dependencies = [
    "importlib-resources",
]

[whyitfor]

What release fixes this issue? I'm asking because 4.12.4.0 does not appear to fix it.

Would be helpful to know if 4.12.5.0 fixes this and when it will be released. We're using Python3.7 and z3-solver is a dependency of a dependency. If a fix is imminent we would wait for it, otherwise we will have to address this in our package.