Disable warn_on_full_buffer via set_wakeup_fd. This avoids tons of
Exception ignored when trying to write to the signal wakeup fd:
BlockingIOError: [Errno 11] Resource temporarily unavailable
that are currently issued after running complex builds. Only works since
Python 3.7, though, so this remains best-effort. Fortunately, the Debian
in our container image is 3.7.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
87af46ff8c