For my automated tests I have a project added to TeamCity server and 2 Agent Pool, one is a Windows Server and the other one is a MAC. The default agent pool is WIN but I wanted to run my tests on the MAC server. To change the agent pool to MAC, I tried to add Agent Requirement by setting teamcity.agent.name to the MAC server from the list but it is not added to list of compatible agents associated with the project, but added to compatible agents with this warning on top of it: Following agents belong to the agent pools which are not associated with "Tests" project where Tests is the name of my project.
How can I associate it MAC agent to my project?
You'll have to add the MAC agent to the agent pool for this project - that's configured in the Agent section available at /agents.html?tab=agentPools for your TeamCity build server.
Alternatively you can create a new agent pool with the MAC agent, and add the project to that pool.