Dynamic versioning with pyproject.toml

[rndubs]

Hi Folks,

I'm using setuptools version 65.4.1 and python 3.7.2.

I am using a pyproject.toml file to package my module, and I would like to set the project version "dynamically" using a datetime-derived version number that is determined at build time. Currently when attempting to build the dist with python3 -m build (build version 0.8.0) I am getting an error, which is provided below.

I've read through the dynamic metadata section of the docs.

Repo Layout

I'm currently attempting to achieve dynamic versioning as follows (only including relevant portions of the repo structure):

mymodule/
├── pyproject.toml
├── mymodule/
│       ├── __init__.py

The mymodule.__init__.py file:

__version__ =  f"{1}.{2}.{3}"  # more complicated than this, but a simple example

A snippet from the pyproject.toml file:

[project]
name = "mymodule"
dynamic = ["version"]

[build-system]
requires = ["setuptools>=61.0.0", "setuptools-scm"]
build-backend = "setuptools.build_meta"

[tool.setuptools.packages.find]
where = ["."]
include = ["mymodule*"]

[tool.setuptools.dynamic]
version = {attr = "mymodule.__version__"}

Current Behavior

Building a wheel and dist with python3 -m build currently results in the following error (not including the full traceback):

...  # full stacktrace snipped here
File "~/python-3.7.2/lib/python3.7/ast.py", line 55, in _convert_num
    raise ValueError('malformed node or string: ' + repr(node))
ValueError: malformed node or string: <_ast.Call object at 0x2aaab1027278>

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/build-env-x7ix9t6m/lib/python3.7/site-packages/setuptools/config/expand.py", line 190, in read_attr
    return getattr(StaticModule(module_name, spec), attr_name)
  File "/build-env-x7ix9t6m/lib/python3.7/site-packages/setuptools/config/expand.py", line 86, in __getattr__
    raise AttributeError(f"{self.name} has no attribute {attr}") from e
AttributeError: mypackage has no attribute __version__

Configuring the mymodule.__init__.py file as follows results in a successful build, but without the desired dynamic versioning at build time:

__version__ =  "1.2.3"

Is there a way to configure my project to include the dynamic versioning info by invoking a function?

[abravalheri]

Hi @rndubs, I cannot reproduce this error with the following experiment (in an isolated docker container):

> docker run --rm -it python:3.7.2 /bin/bash
python -m pip install -U pip 'setuptools==65.4.1' build
mkdir -p /tmp/myproj/mymodule
cd /tmp/myproj
echo -e '__version__ = f"{1}.{2}.{3}"' > mymodule/__init__.py
cat <<EOS > pyproject.toml
[project]
name = "mymodule"
dynamic = ["version"]

[build-system]
requires = ["setuptools>=61.0.0", "setuptools-scm"]
build-backend = "setuptools.build_meta"

[tool.setuptools.packages.find]
where = ["."]
include = ["mymodule*"]

[tool.setuptools.dynamic]
version = {attr = "mymodule.__version__"}
EOS
python -m build

This successfully creates the mymodule-1.2.3-py3-none-any.whl distribution.

If I replace the __init__.py with the following

echo -e 'a = 4\nb = 5\nc = 6\n__version__ = f"{a}.{b}.{c}"' > mymodule/__init__.py

and run python -m build again, it will successfully create a mymodule-4.5.6-py3-none-any.whl distribution.