https://libre-soc.org/irclog/%23libre-soc.2021-07-24.log.html#t2021-07-24T11:51:16
explanation of what happened: https://libre-soc.org/irclog/%23libre-soc.2021-07-27.log.html#t2021-07-27T09:07:22
I fixed it, and created a libre-soc-install.sh script that should work for old versions of pip (tested with version 18.1).