For processes created with :func:`~asyncio.create_subprocess_exec`, a negative

value ``-N`` indicates that the child was terminated by signal ``N``

(POSIX only).

For processes created with :func:`~asyncio.create_subprocess_shell`, the

return code reflects the exit status of the shell itself (e.g. ``/bin/sh``),

which may map signals to codes such as ``128+N``. See the

documentation of the shell (for example, the Bash manual's Exit Status)

for details.