useless backtrace on Ctrl-C
$ meson .. [wait a bit, press Ctrl-C while it's still running]
Results: prints a python backtrace. While that's customary for python programmes, it's just noise to the user. Should suppress that and just exit on Ctrl-C.
$ meson .. [wait a bit, press Ctrl-C while it's still running]
Results: prints a python backtrace. While that's customary for python programmes, it's just noise to the user. Should suppress that and just exit on Ctrl-C.