CONFIG_LOCALMIRROR, how to get the list of URLs?

For Developers
1

I'm glad that CONFIG_LOCALMIRROR exists, but how do I get it to print out a list of URLs that I need to set up the mirror in the first place?

2

This would be especially useful while gnu.org is down https://hostux.social/@fsfstatus/113230041959498522

(this also takes out ftpmirror.gnu.org, lol)