Ubuntu 14.04 / GTX 760
Broken: (2.74 RC4 3593082)
Worked: (2.73, 2.74 RC3)
Short description of error
Group inputs have no effects inside group.
Exact steps for others to reproduce the error
Open the file, make a render and change value of the node group. It does nothing on 2.74 RC4 but works well on the 2.73.