[BUG]: Build-time deprecation warning about `project.license` usage

[miketheman]

Tracer Version(s)

3.10.2

Python Version(s)

Python 3.13

Pip Version(s)

pip 25.0.1

Bug Report

During pip install from a source distribution (i.e. triggering a build, not using a wheel), a deprecation warning is emitted.

Stems from:

dd-trace-py/pyproject.toml

Line 10 in 07d0791

license = { text = "LICENSE.BSD3" }

See here for guidance on resolution: https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license

Reproduction Code

pip install --no-binary :all: ddtrace==3.10.2

Error Logs

...
117.5   × Building wheel for ddtrace (pyproject.toml) did not run successfully.
117.5   │ exit code: 1
117.5   ╰─> [8349 lines of output]
117.5       <string>:26: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
117.5       <string>:28: DeprecationWarning: dep_util is Deprecated. Use functions from setuptools instead.
117.5       INFO: DD_FAST_BUILD not enabled
117.5       /tmp/pip-build-env-cbz4duhq/overlay/lib/python3.13/site-packages/setuptools/config/_apply_pyprojecttoml.py:82: SetuptoolsDeprecationWarning: `project.license` as a TOML table is deprecated
117.5       !!
117.5
117.5               ********************************************************************************
117.5               Please use a simple string containing a SPDX expression for `project.license`. You can also use `project.license-files`. (Both options available on setuptools>=77.0.0).
117.5
117.5               By 2026-Feb-18, you need to update your project and remove deprecated calls
117.5               or your builds will no longer be supported.
117.5
117.5               See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
117.5               ********************************************************************************
117.5
117.5       !!
117.5         corresp(dist, value, root_dir)
...

Libraries in Use

n/a

Operating System

n/a

[miketheman]

This can also be seen in the CI jobs, here's a recent one on the Build source distribution step: https://github.com/DataDog/dd-trace-py/actions/runs/16222013273/job/45804653342?pr=13951#step:5:95

[miketheman]

This should also be a good time to handle this warning as well

/private/var/folders/qr/txsjh_sx5z12f2cn_vvw4fh40000gn/T/pip-build-env-bc9rc9u4/overlay/lib/python3.13/site-packages/setuptools/dist.py:759: SetuptoolsDeprecationWarning: License classifiers are deprecated.
            !!

                    ********************************************************************************
                    Please consider removing the following classifiers in favor of a SPDX license expression:

                    License :: OSI Approved :: Apache Software License
                    License :: OSI Approved :: BSD License

                    See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
                    ********************************************************************************

            !!
              self._finalize_license_expression()