How to add a (TFS 2008) build agent to a TFS 2013 build controller that is also a build agent?

Question

We're working on migrating our build solution from TFS 2008 to TFS 2013. As a part of that process, I am trying to add a clone of (one of) the current build agents (based on TFS 2008 and Visual Studio 2010) to the new TFS 2013 build controller, to make sure that we have the ability to run builds with the same environment that we do now. (This capability will be needed for some time e.g. for minor updates, hotfixes etc.) The clone has been created, started, and given a separate DNS name on the network, to allow it to be addressed.

Currently, our new environment has a TFS server, as well as a build server that hosts both the build controller and one build agent; all TFS 2013. (I'd rather see that the build controller at least ran on the TFS server VM, or ideally on a completely separate VM, but this is what it's like right now.)

When I log in to the new build controller/agent and run the Team Foundation Server Administration Console, then go into Build Configuration under that host's root node, it shows the build controller as well as the build agent (both with the same name because they are running on the same VM).

When I click "New Agent...", I expect to be able to add a new build agent (that's what the link says, after all). This is also what Microsoft indicates you should do in their documentation. However, what happens is that I get a window titled "Build Agent Properties" that appears to show the details for the existing build agent configuration. Specifically, it pre-populates the "Computer Name" field with the name of the existing build agent and has selected the existing (TFS 2013) build controller. The "Build Agent service is enabled" checkbox is checked, but the box immediately underneath that checkbox says "Build Agent status is Offline". In the main administration console window, both the controller and agent show as "Ready", and they have executed builds previously. I also cannot edit the "Computer Name" field.

So, to recap:

When the TFS 2013 build controller is also a TFS 2013 build agent, how do I add a second (TFS 2008-based, in my case) build agent to the build controller?

I imagine I'm missing something really trivial, but I just cannot see what, and Googling has turned up seemingly nothing of relevance.

Answer 1

Click "New Agent...", change the 'display name', click ok and you'll get a new (2013) build agent.

You're going to have to upgrade your existing 2008 build agent. IIRC 2010 build agents only connect to 2012 controllers if they're patched with sp1 so you've got no chance with 2008.