Indeed, after reverting to py3-aiohttp-3.13.0 as of 2025-10-18
vdirsyncer is happy again. 

I wonder why your use case is not impacted. 
Do you use authentication?
I would not have thought that my use case is non-trivial :-)
Just syncing a couple of calenders and contact books from a
caldav/carddav server (SOGo) to local file storage.

I'll now return to newer aiohttp and try the newer version of
vdirsyncer you sent.

Thanks, Marcus

stu@spacehopper.org (Stuart Henderson), 2025.12.06 (Sat) 17:06 (CET):
> my (trivial) use of vdirsyncer is still working.
> 
> can you try reverting to older py3-aiohttp without touching anything
> else to confirm that this is indeed the source of the problem?
> 
> there were some changes around netrc handling which might possibly be
> relevant.
> 
> 
> On 2025/12/06 17:41, Marcus MERIGHI wrote:
> > Hello, 
> > 
> > first noticed today, on -current amd64 as of yesterday evening, CET,
> > vdirsyncer fails for me.
> > 
> > Am I the only one hit by this?
> > 
> > Both ends (client vdirsyncer, server sogo) are under my control and
> > nothing has change regarding configuration.
> > 
> > The error is:
> > error: Unknown error occurred for
> >         fifi_cal/fifi_94C2-66B08F00-E9-711CAC80: CannotG combine
> >         AUTHORIZATION header with AUTH argument or credentials encoded
> >         in URL 
> > error: Use `-vdebug` to see the full traceback.
> > 
> > With -vdebug I get a huge trace of course, the last lines being:
> > debug:   File
> >         "/usr/local/lib/python3.13/site-packages/vdirsyncer/http.py",
> >         line 184, in request
> > debug:     response = await session.request(method, url,
> >         headers=headers, **kwargs)
> > debug: ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > debug:   File
> >         "/usr/local/lib/python3.13/site-packages/aiohttp/client.py",
> >         line 676, in _request
> > debug:     raise ValueError(
> > debug:     ...<3 lines>...
> > debug:     )
> > 
> > So py3-aiohttp seems to start the error chain.
> > 
> > I checked and www/py3-aiohttp was recently updated to 3.13.2, from
> > 3.13.0. 
> > 
> > When I look at 
> > https://docs.aiohttp.org/en/stable/changes.html
> > nothing stands out between 3.13.0 (working) and 3.13.2 (not working)
> > with an eye on "Cannot combine AUTHORIZATION header with AUTH argument
> > or credentials encoded in URL".
> > 
> > Also the issues page of vdirsyncer at
> > https://github.com/pimutils/vdirsyncer/issues
> > does not show any recent issues with changes in py3-aiohttp.
> > 
> > The Web is not very helpful, either.
> > 
> > Does anyone have an idea what is going on?
> > 
> > The versions involved are:
> > py3-aiocache-0.12.3p0
> > py3-aiodns-3.2.0p1
> > py3-aiohappyeyeballs-2.6.1p0
> > py3-aiohttp-3.13.2
> > py3-aiohttp-oauthlib-0.1.0p2
> > py3-aiomcache-0.8.2p1
> > py3-aioquic-1.2.0p1
> > py3-aiosignal-1.4.0p1
> > py3-aiosqlite-0.21.0p0
> > py3-aiostream-0.7.1
> > vdirsyncer-0.19.3p0
> > 
> > Thanks for reading that far, Marcus
> > 
>