Achim Gratz writes:
>>> There is some undesirable interaction when I try to start mintty from my
>>> desktop shortcut.  Mintty itself starts OK, but any Cygwin program that
>>> mintty starts (whether a shell or something else) just goes into a
>>> spinloop (Windows says it's mostly kernel time).

Unfortunately it seems I will not be able to keep at 3.0.7 for much
longer as octave already depends on the CPU affinity changes in 3.1.x,
so my choice is to either have octave or mintty working… :-(

Meanwhile we got two new lab PC so I could there as well.  They have a
different enough installation from my laptop that if it's related to
that I should see something.  However, reproducibly it's my work account
that has the problem of not getting a mintty started and another account
that I can use just works.  I can actually start a cmd (or other Windows
program) inside mintty and have it work, I can then also start my shell
and it will show me /dev/cons0 as the tty.  Again, trying to strace the
mintty start gets me a segfault after touching a lot of addresses that
it shouldn't touch.  Doing the same exercise without strace gets an
unresponsive mintty window (most of the time), and later attaching to
the running shell inside reveals it is livelocked on acquiring some pty
master mutex.