Problem
On Fedora 44, Element Synapse (a Matrix server) fails to start with the following traceback:
/usr/lib64/python3.14/site-packages/synapse/config/_base.py:49: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest>
import pkg_resources
/usr/lib64/python3.14/site-packages/synapse/_pydantic_compat.py:36: UserWarning: Core Pydantic V1 functionality isn't compatible with Python 3.14 or greater.
from pydantic.v1 import (
Traceback (most recent call last):
File "<frozen runpy>", line 198, in _run_module_as_main
File "<frozen runpy>", line 88, in _run_code
File "/usr/lib64/python3.14/site-packages/synapse/app/homeserver.py", line 34, in <module>
...
...
raise errors_.ConfigError(f'unable to infer type for attribute "{self.name}"')
pydantic.v1.errors.ConfigError: unable to infer type for attribute "secret"
Cause
The rpm of Element Synapse rpm failed to build on Fedora 44 and is stuck on a old version of the code ( 1.137.0 ) using pydantic v1, who is not compatible with Python 3.14. A newer version using Pydantic v2 is needed per upstream, but it doesn’t build on F44 due to missing dependencies that have been orphaned and/or not packaged yet.
Related Issues
Bugzilla report: #2434810
Upstream ticket: cannot install Synapse on fedora minimal v43 with Python v3.14 - Pydantic v1 errors · Issue #19130 · element-hq/synapse · GitHub
Workarounds
None yet.