=> "/opt/pkg/bin/bmake" ["-C", "/data/jenkins/workspace/pkgsrc-upstream-trunk/net/Radicale2", "all", "PYTHON_VERSION_REQD=311", "BATCH=1", "DEPENDS_TARGET=/nonexistent"]
===> Building for Radicale-2.1.12nb5
* Building wheel...

Traceback (most recent call last):
  File "/opt/pkg/lib/python3.11/site-packages/pyproject_hooks/_impl.py", line 402, in _call_hook
    raise BackendUnavailable(
pyproject_hooks._impl.BackendUnavailable: Cannot import 'setuptools.build_meta'

TIP pass --env-dir and --sdist-extract-dir to keep the build environment and sources, then see https://build.pypa.io/en/stable/how-to/troubleshooting.html#debug-a-failed-build for help debugging a failed build
ERROR Backend 'setuptools.build_meta:__legacy__' is not available.
*** Error code 1

Stop.
bmake[1]: stopped making "all" in /data/jenkins/workspace/pkgsrc-upstream-trunk/net/Radicale2
*** Error code 1

Stop.
bmake: stopped making "all" in /data/jenkins/workspace/pkgsrc-upstream-trunk/net/Radicale2