Exit value 141 means
git received SIGPIPE, that is to say the process tried
to write to a pipe that was closed. This usually means that your pre-push hook
took too long to run, and thus the connection to your upstream provider was
closed. You can fix this by making ssh send keepalive messages to your upstream provider.
For instance, for gitlab.com, you would add the following to
Host gitlab.com ServerAliveInterval 60 ServerAliveCountMax 10
Adjust ServerAliveCountMax to around the number of minutes your pre-push hook takes to run.