trafficserver stretch backports version do not start

[titus_debian@netcourrier.com]

Hello,

I hope my first feedback will be useful and in the good place ...

Problem with Apache Traffic Server stretch backports version.

Tested on physical and virtual machines. The stable version runs ok.

On the backports version, systemctl status trafficserver says:

traffic_cop[954]: unable to locate local state directory '/var/run/trafficserver'

traffic_cop[954]: please try setting correct root path in either env variable TS_ROOT

just ask if other infos needed