All right, here are my findings
When attempting to download the SPL for F030 the sw4stm32 requests a zip file from this URL
but gets 404 Not Found (discovered via wireshark; you can check the url yourselves). The file is not there.
All the firmware archives (including HAL) are defined in this XML file:
.. meaning one could possibly change the path and all we will be happy.
At the beginning of the file there are four servers, but the download process is terminated already when with the first attempt fails. Right the second server works (almost fine)
and the rest of the servers is dead either.
Therefore, I hoped when I place the (manually) working URL at the first position, the download may work just fine. Surely, it doesn’t. The URL, although being downloadable from the browser returns 301 (Moved Permanently) on which the IDE’s downloader fails again.
Trying it out with wget, that redirect eventually leads to https://www.st.com/content/ccc/resource/technical/sw-updater/firmware2/7f/35/cc/ee/e6/80/42/29/stm32f0_stdperiph_lib_v150.zip/files/stm32f0_stdperiph_lib_v150.zip/jcr:content/translations/en.stm32f0_stdperiph_lib_v150.zip where the firmware is eventually located.
Having added the most of this url to the server list at the first position, the firmware gets downloaded and installed successfully!
BUT: The “server” URL contains the filename repeatedly so it cannot be used as general address. I suggest the current state of the firmware locations shall be updated and firmware archives perhaps even mirrored (backed-up) somewhere for the eventuality the ST folks decide to remove even the last working mirror. Another question is, whether this URL can be taken as an universal template or the magic numbers are dynamically generated by whichever algorithm.
Same solution can be also used for the STM32F103CBTx which url
eventually goes to
Now I deserve a beer..