If the system does restart what will happen to weewx? Will it still run for 
a while and then just stop?

On Friday, 17 July 2026 at 08:52:29 UTC+10 Greg from Oz wrote:

> Thanks John. I have read all of that on the link you gave me but it makes 
> no sense to me at all as I am no programmer. I just use the software. I 
> guess I will wait for the fix to appear. 
>
> On Friday, 17 July 2026 at 03:20:24 UTC+10 Vince Skahan wrote:
>
>> I know John strongly disagrees but this is another reason why I do not 
>> do ‘any’ package updates on my LAN-only weewx system. I get it working and 
>> leave it alone.  Granted my risk profile permits this for me. I permit ‘no’ 
>> incoming traffic to my LAN that the weewx system is on,
>>
>> Running in docker is another way to avoid these kinds of ‘sand shifted 
>> under your feet’ problems, making it easier to revert to a previously 
>> stable setup.
>>
>> (but wow quite the elaborate investigation figuring out all the gory 
>> internals things for this case)
>>
>> On Thursday, July 16, 2026 at 8:13:32 AM UTC-7 John Kline wrote:
>>
>>> Hi Greg,
>>>
>>> I pinged the maintainer (Stefano) on the bug.  Stefano already has a 
>>> test build of 3.13.5-2+deb13u4.  See his reply here: 
>>> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1141977 for a link to 
>>> it (if you want to install it).  I have it running on 7 machines and will 
>>> do the rest after the first weewx gc run in about 2 and 1/2 hours.
>>>
>>> John
>>>
>>> On Jul 15, 2026, at 6:48 PM, John Kline <[email protected]> wrote:
>>>
>>> 
>>>
>>> Well, you can from a Debian snapshot, but I think if I listed 
>>> instructions on how to do that, I dig myself quite a hole in having to 
>>> support the process; and, I suspect, some will never undo putting the 
>>> packages on hold, thus, never get a python upgrade again.
>>>
>>> On Jul 15, 2026, at 4:05 PM, Greg from Oz <[email protected]> wrote:
>>>
>>> apt-cache policy python3.13
>>> python3.13:
>>>   Installed: 3.13.5-2+deb13u3
>>>   Candidate: 3.13.5-2+deb13u3
>>>   Version table:
>>>  *** 3.13.5-2+deb13u3 500
>>>         500 http://deb.debian.org/debian trixie/main amd64 Packages
>>>         100 /var/lib/dpkg/status
>>>
>>> Looks like I cannot downgrade...I will just have to now restart the 
>>> weewx.
>>> I do have weewx set up in monit and if it does crash in theory it should 
>>> restart again.
>>>
>>>
>>> On Wednesday, 15 July 2026 at 23:05:03 UTC+10 John Kline wrote:
>>>
>>>> I believe the maintainers have what they need to push a fix.  I’m 
>>>> hoping that will happen in a week or two.
>>>>
>>>> >> At least if it doesn't start I will know what to do
>>>>
>>>> It will start just fine.  The issue is, each time weewx requests 
>>>> garbage collection (which, by default, weewx does every 3 hours), there is 
>>>> a small chance of a segment violation soon after.  As such, the symptom 
>>>> will be that weewx stops running for no obvious reason (and nothing in the 
>>>> log after a garbage collection message).
>>>>
>>>> It is hard to say how often this might happen for a single instance of 
>>>> weewx running.  The frequency may depend on what extensions you are 
>>>> running 
>>>> (and how many of them).  It is conceivable that some won’t see the issue 
>>>> at 
>>>> all before the fix arrives.
>>>>
>>>> I was seeing the issue too often (as I run quite a few weewx 
>>>> instances);  so I resorted to downgrading the python packages and put them 
>>>> on hold while waiting for the update.
>>>>
>>>> John
>>>>
>>>> On Jul 15, 2026, at 2:53 AM, Greg from Oz <[email protected]> wrote:
>>>>
>>>> 
>>>>
>>>> So when does the new fix arrive?
>>>> I upgraded the python 2 days ago and weewx has been running for 4 
>>>> days....I better not restart weewx.
>>>> At least if it doesn't start I will know what to do...Thanks for the 
>>>> heads up.
>>>>
>>>> On Tuesday, 14 July 2026 at 08:17:42 UTC+10 Tom Keffer wrote:
>>>>
>>>>> Thanks, John, for your detailed report.
>>>>>
>>>>> On Mon, Jul 13, 2026 at 8:09 AM 'John Kline' via weewx-user <
>>>>> [email protected]> wrote:
>>>>>
>>>>>> If you run WeeWX on Debian 13 (trixie) and your system installed the
>>>>>> python3.13 update from the 13.6 point release (version 
>>>>>> 3.13.5-2+deb13u3,
>>>>>> rolling out via unattended-upgrades since July 11), be aware that it 
>>>>>> can
>>>>>> crash weewxd with a segmentation fault.
>>>>>>
>>>>>> What it looks like
>>>>>> ------------------
>>>>>> weewxd dies with SIGSEGV -- no Python traceback in the log, the 
>>>>>> process
>>>>>> just exits.  systemd shows "Main process exited, code=dumped,
>>>>>> status=11/SEGV".  If you look closely at the timing, the crash comes
>>>>>> milliseconds after WeeWX's periodic garbage collection pass (the
>>>>>> "Garbage collected N objects" INFO line, every 3 hours by default).
>>>>>> weewxd is unusually good at tripping this bug precisely because it 
>>>>>> calls
>>>>>> gc.collect() on that schedule while its other threads keep working.
>>>>>>
>>>>>> I run seven WeeWX machines (Raspberry Pi 5, all on trixie).  Four 
>>>>>> crashes
>>>>>> in the ~48 hours after the update reached them; the crash takes down 
>>>>>> maybe
>>>>>> 1 in 25 GC passes, so it looks random and can hit anywhere from hours 
>>>>>> to
>>>>>> days after a restart.  The crashing thread differs every time (sqlite
>>>>>> reads, report generation, image generation), so don't chase whatever
>>>>>> happens to be in your traceback if you have faulthandler enabled -- 
>>>>>> it's
>>>>>> the victim, not the cause.
>>>>>>
>>>>>> The cause
>>>>>> ---------
>>>>>> It is not WeeWX and not any extension.  Debian's deb13u3 update 
>>>>>> backported
>>>>>> a garbage-collector fix into Python 3.13.5 but omitted a second 
>>>>>> upstream
>>>>>> commit that the fix depends on, so a GC pass can free memory that is 
>>>>>> still
>>>>>> in use.  It's tracked as Debian bug #1141977, the missing commit has 
>>>>>> been
>>>>>> identified by bisection, and the maintainer is engaged, so I'd expect 
>>>>>> a
>>>>>> fixed package (deb13u4) reasonably soon:
>>>>>>
>>>>>>   https://bugs.debian.org/1141977
>>>>>>
>>>>>> Am I affected?
>>>>>> --------------
>>>>>>   dpkg -l python3.13 | grep deb13u3
>>>>>>
>>>>>> Two things must both be true: the deb13u3 package is installed AND 
>>>>>> weewxd
>>>>>> was (re)started after it was installed.  A weewxd that has been 
>>>>>> running
>>>>>> since before the upgrade still uses the old library and is safe until 
>>>>>> its
>>>>>> next restart.
>>>>>>
>>>>>> What to do
>>>>>> ----------
>>>>>> 1. If your weewxd predates the upgrade, simply don't restart it until 
>>>>>> the
>>>>>>    fixed package arrives.
>>>>>> 2. Otherwise, make crashes self-healing while you wait.  A systemd
>>>>>>    drop-in (systemctl edit weewx) with:
>>>>>>
>>>>>>      [Service]
>>>>>>      Restart=on-failure
>>>>>>      RestartSec=10
>>>>>>
>>>>>>    turns each crash into ~15 seconds of downtime.  I also recommend
>>>>>>    Environment=PYTHONFAULTHANDLER=1 there -- it logs a full thread 
>>>>>> dump
>>>>>>    on any future native crash, which is invaluable for problems like
>>>>>>    this one.
>>>>>> 3. Raising gc_interval in weewx.conf reduces exposure but does not
>>>>>>    eliminate it (Python's automatic collections use the same broken
>>>>>>    code path), so I wouldn't rely on it.
>>>>>> 4. When the fixed python3.13 package arrives, remember that a running
>>>>>>    weewxd keeps the old library until it is restarted -- do a
>>>>>>    "systemctl restart weewx" after the upgrade to actually get off the
>>>>>>    broken version.
>>>>>>
>>>>>> Downgrading to deb13u2 also works but re-opens the security fixes that
>>>>>> update carried; with the auto-restart in place I don't think it's 
>>>>>> worth
>>>>>> it.
>>>>>>
>>>>>> John
>>>>>>
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>>>>>> https://groups.google.com/d/msgid/weewx-user/92B83A5B-A968-4531-8DF2-223C1E9D1ED7%40johnkline.com
>>>>>>  
>>>>>> <https://groups.google.com/d/msgid/weewx-user/92B83A5B-A968-4531-8DF2-223C1E9D1ED7%40johnkline.com?utm_medium=email&utm_source=footer>
>>>>>> .
>>>>>>
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>>>>  
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>>>> .
>>>>
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