Just in case any of you were wondering (like I was) why the Appveyour builds are currently failing, it’s this:
It’s a problem with MSYS2. We need to wait until Appveyor updates the pre-installed MSYS2 they provide.
Yes, I have been wondering, but hadn’t taken a closer look yet.
As a temporary workaround, it seems possible to use
- pacman -Sy --noconfirm pacman
- pacman -Su --noconfirm
Some people in that endless thread said that this does not work, or causes additional issues. Unless we’re a hurry, it might save some trouble to just wait a couple of days.
(When I updated msys2 on my own machine, it required a reboot before it would work again.)
Ah yes, a reboot sounds difficult 
No problem to wait I think!