GitLab is used only for code review, issue tracking and project management. Canonical locations for source code are still https://gitweb.torproject.org/ https://git.torproject.org/ and git-rw.torproject.org.
dkg discovers in https://bugs.debian.org/851798 that Tor's SocksPort defaults to IPv6traffic 0.
But Tor Browser set it to 1 18 months ago in #16684 (moved).
It looks like Tor 0.2.4.7-alpha, back in 2012, decided to "wait for enough exits to support IPv6" before turning it on.
Has that time arrived?