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>