[Pkg-matrix-maintainers] Bug#1128500: matrix-synapse: fails to start when python3-eventlet is installed

[Andrej Shadura]

Control: reassign -1 src:sentry-python

Hello,

On Fri, 20 Feb 2026, at 17:15, Gena Byers wrote:
> On 2/20/26 4:54 PM, Andrej Shadura wrote:
>> Can you give me more details please?
>> I don’t see any mentions of this anywhere in the source.

> I don't know what the exact mechanism is but installing python3-eventlet 
> renders matrix-synapse inoperable:

> "/usr/lib/python3/dist-packages/sentry_sdk/utils.py", line 1346, in 
> _get_contextvars
> Feb 20 16:59:17 nexus python3[2979902]:     if not _is_contextvars_broken():
> Feb 20 16:59:17 nexus python3[2979902]:            ~~~~~~~~~~~~~~~~~~~~~~^^
> Feb 20 16:59:17 nexus python3[2979902]:   File 
> "/usr/lib/python3/dist-packages/sentry_sdk/utils.py", line 1287, in 
> _is_contextvars_broken
> Feb 20 16:59:17 nexus python3[2979902]:     from eventlet.patcher import 
> is_monkey_patched  # type: ignore

Looks like something in the sentry SDK (which I think you should have mentioned you enabled).

-- 
Cheers,
  Andrej