How to specify the `--formats` sdist option inside setup.py?

I try to create a zipped source python package on a linux distribution without specifying the --formats option to sdist on the command line (using an existing Jenkins pipeline which do not support this option). In the documentation here, it states:

(assuming you haven’t specified any sdist options in the setup script or config file), sdist creates the archive of the default format for the current platform. The default format is a gzip’ed tar file (.tar.gz) on Unix, and ZIP file on Windows.

But it doesn't say how should you specify sdist options in the setup script?

Solution

From the linked documentation previous topic:

The basic syntax of the configuration file is simple:
[command]
option=value
...
where command is one of the Distutils commands (e.g. build_py, install), and option is one of the options that command supports

and later an example for build_ext --inplace

[build_ext]
inplace=1

That means that you must write into the setup.cfg file:

[sdist]
formats=zip

Beware: untested because I have no available Python2...