I don't want any Mac I run that might be available to the public (i.e. left in a hotel room in a nosy foreign country) to store my ssh pass phrase in the machine.
In
/System/Library/LaunchAgents/org.openbsd.ssh-agent.plistadd to the ProgramArguments array:
<string>-t</string> <string>60</string>so the agent only hangs around for 60 seconds.