TL;DR: X2Go Client for Windows builds will be down temporarily.
Hopefully the VM will not be upgraded from Windows 7 to 10 (probably
very disruptive) or have future issues with Windows Updates.
I tried to get dismiss the "Get Windows 10" prompt, but accidentally
started the upgrade.
I am taking steps to both disable the upgrade (so far, so good) and
clean up disk space on C:\
This involves moving the old Cygwin installs from C:\ to D:\.,
including the install where sshd runs from.