ssh -f -n option unexpectedly blocks the job #769
Description
The job (https://testflinger.canonical.com/jobs/c057b99a-16a8-4d67-b54e-5ce826d2e5f2) got the results "output timeout reached (900s)".
job_queue: sonic-ci
provision_data:
distro: jammy
test_data:
test_cmds: |
ssh -f -n ubuntu@$DEVICE_IP "cd /xxx/xxx && python3 -m http.server 8080"The test phase of the above job never finishes and gets blocked until the output timeout reached.
However, running the ssh -f -n command directly or running a shell script with this command don't get blocked.
(The workaround: ssh ubuntu@$DEVICE_IP "nohup python3 -m http.server 8080 --directory path_to_dir > /dev/null 2>&1 &")