As you may know I worked on TFS Branch Tool which is one of the ALM Rangers solutions. As usual we are dogfooding latest technology and at some point our builds started failing. We tried to investigate cause and found that product team deployed latest VS 2013 bits into golden image of the agent. We identified that some of the tests that use Microsoft Fakes are failing on hosted build. Don’t be surprised that everything was fine on developer’s computer. So, business as usual.