Sid is up-to-date as of Oct 6th.
I login like normal, the screen turns grey with the cursor still visible, and
then, I see a terminal screen and GDM3 returns, requiring me to login at least
one more time. On two occasions, it just kept repeating the terminal-to-gdm3
loop without logging in. On at least on of those times, when I logged in on
t2, I was able to login successfully afterwards; though, it should be noted, I
was trying to get around the problem by telling the system to switch to lightdm
(but gdm3 was still on the screen, and magically worked.)
Most of the time, I have to relaunch my extensions after logging in (there may
have literally been two exceptions to that, and I *THINK* one of them was after
the purge mentioned below.)
I've had this issue with gdm3 only on this laptop, but for both GNOMEs 46 and
47.
I have purged gdm3; switched to lightdm; purged lightdm; reinstalled gdm3 and
still had this problem.