I have just tested it without success.
This is my config:
[Unit]
Description=Hyperion Systemd service
[Service]
Type=simple
User=root
Group=root
UMask=007
ExecStart=/usr/bin/hyperiond /etc/hyperion/hyperion.config.json
ExecReload=/bin/kill -HUP $MAINPID
Restart=on-failure
TimeoutStopSec=10
RestartSec=20
[Install]
WantedBy=multi-user.target
Anybody having further ideas?
If I open a console and enter:
sudo killall hyperiond
sudo service hyperion start
nohup hyperion-v4l2 &
... it starts immediately.