1) install squid3 (wily)
2) systemd is able to start/stop squid3
3) break the config (add a syntax error that prevents squid3 from starting)
4) neither manual nor systemd startup of squid3 work (expected)
5) fix the config
6) manual startup works again (expected), systemctl start squid3 does not (unexpected)
Steps to reproduce:
1) install squid3 (wily)
2) systemd is able to start/stop squid3
3) break the config (add a syntax error that prevents squid3 from starting)
4) neither manual nor systemd startup of squid3 work (expected)
5) fix the config
6) manual startup works again (expected), systemctl start squid3 does not (unexpected)