cmake errors when compiling ros_comm from source

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Hello,

I am trying to build ros_comm from source, since I am on a platform which has boost 1.62 and the downloaded package for my arm64 architecture is seemingly stuck at 1.58.

My nodes compile beautifully if I ignore the warnings and use the repo packages (apt-get ros-kinetic-ros-comm), but fails when I try to fix the boost warnings by compiling by source.

The message I get is:

CMake Error at /ws/build/ros_comm/clients/roscpp/cmake/roscpp-genmsg.cmake:79 (add_custom_target):
  add_custom_target cannot create target "roscpp_generate_messages_cpp"
  because another target with the same name already exists.  The existing
  target is a custom target created in source directory
  "/ws/src/my_node".  See documentation for policy
  CMP0002 for more details.

Call Stack (most recent call first):
  /opt/ros/kinetic/share/genmsg/cmake/genmsg-extras.cmake:307 (include)
  ros_comm/clients/roscpp/CMakeLists.txt:39 (generate_messages)

It feels like it's conflicting with the original installation somehow, but I've already tried apt-get removing the original.

What's the best way to fix this error?