This message was posted on behalf of Intel Corporation
There were changes to the Intel RealSense Github and we need to update our source file to pull from the right branch. In short, librealsense (v1) was moved to legacy and librealsense2 (v2) is the master branch.
Take a look at this thread: https://communities.intel.com/message/553783 the correct answer shows the steps to get a successful build.
Intel Customer Support