TFS 2010: Why do team builds run for a long time?

has recently been using visual Studio 2010 to develop silverligth based projects and has used team Foundation server as the management tool for the entire development process. To ensure that the embedding of each other in the development process does not affect each other, we have configured the team Build Service and used the gated Check-in (reference Team Build 2010–gated Check-in to reject code that cannot be compiled for embedding knowledge gated Check-in) to control that everyone's embedded code can be successfully compiled by the team build. In the first few days, team builds are working and efficient. But suddenly one day found gated check-in run for up to 6 hours but still unable to end, and a lot of quiet continue to run for a long time momentum, the problem?

Figure 1-Runs a 6-hour team Build Instance

Open the current build instance to see what's going on. From the image below we can see that all of the test has been run and passed, and the test Settings and test impact have all been run and reviewed, and the next publish work is done, so what is it doing next? We don't know, because through here we don't see what else needs to be done.

Figure 2-The last action of the currently running Team Build