haawda [1] filed a request to merge luatex-svn [2] into luatex-git [3]:

The sources in the svn repo are no longer publicly available. See also https://tex.stackexchange.com/questions/397249/reading-luatex- source?rq=1

The github mirror seems to be official.

[1] https://aur.archlinux.org/account/haawda/ [2] https://aur.archlinux.org/pkgbase/luatex-svn/ [3] https://aur.archlinux.org/pkgbase/luatex-git/