Restricting a configuration to run on a particular agent

Hi,

Im trying to make it so a configuration only runs on one particular agent.

I have tried adding an agent requirement to the configuration, which compares the system.%system.agent.name% property to the name of the build agent I want to restrict it to.

But this does not work. Infact if I do a exists check on system.%system.agent.name%, it seems that this property does not even exist.

What am I doing wrong?