Thanks a lot for your help!
spoiler
My next move was to try and install https://github.com/jpillora/chisel to fetch the content via git protocol through the proxy because I cannot force git(1) to use the SOCKS5 proxy (no option seems to work: it’s only with https or http). So, maybe chisel was just there for the rhyme. Still trying…
Ses justifications sont tellement abjectes et assumées dans l'odieux qu'elles me donnent envie de vomir.