skyfield.almanac error downloading ephemeris OSError

[Tomasz Lewicki]

Hi users.

I'd like to ask how to get rid of message ERROR user.skyfieldalmanac: thread 'SkyfieldMaintenanceThread': error downloading ephemeris OSError - cannot download https://ssd.jpl.nasa.gov/ftp/eph/planets/bsp/de440s.bsp because <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self-signed certificate in certificate chain (_ssl.c:992)> or rather what to change in my configuration to download the file.

[michael.k...@gmx.at]

Check the certificate chain.

How does it look at your place? And why is there a self-signed certificate in the chain? And most important: do you think this is okay?

Workaround: download the file manually and copy it to the archive/skyfield folder of your WeeWX installation.

[Tomasz Lewicki]

Thank you for your reply. In the meantime, the problem solved itself. A few days ago, in another thread, I asked about repairing the weewx.db database, which was showing errors – possibly due to a damaged memory card (I use Raspberry Pi). This was the most likely cause, as other services running in parallel with Weewx also started to behave strangely. At the last minute, I cloned the card to a new one and, at the same time, upgraded the operating system from Raspbian 12 (bookworm) to 13 (trixie). The SSL certificates were also updated, and that seems to have solved the problem with the refusal to download the de440s.bsp file - I already have it in the /var/lib/weewx/skyfield directory with yesterday's date, and the error messages have disappeared from the log.