Issue with compilation of rospack

[nh-125]

Hi I'm trying to install onto a raspberry pi and I keep getting this error about not having boost/tr1/unordered_set.hpp

==> Processing catkin package: 'rospack'
==> Building with env: '/opt/ros/kinetic/env.sh'
==> cmake /home/pi/ros_catkin_ws/src/rospack -DCATKIN_DEVEL_PREFIX=/home/pi/ros_catkin_ws/devel_isolated/rospack -DCMAKE_INSTALL_PREFIX=/opt/ros/kinetic -DCMAKE_BUILD_MAKE=Release -G Unix Makefiles in '/home/pi/ros_catkin_ws/build_isolated/rospack'
CMake Warning (dev) at CMakeLists.txt:2 (project):
  Policy CMP0048 is not set: project() command manages VERSION variables.
  Run "cmake --help-policy CMP0048" for policy details.  Use the cmake_policy
  command to set the policy and suppress this warning.

  The following variable(s) would be set to empty:

    CMAKE_PROJECT_VERSION
    CMAKE_PROJECT_VERSION_MAJOR
    CMAKE_PROJECT_VERSION_MINOR
    CMAKE_PROJECT_VERSION_PATCH
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Using CATKIN_DEVEL_PREFIX: /home/pi/ros_catkin_ws/devel_isolated/rospack
-- Using CMAKE_PREFIX_PATH: /opt/ros/kinetic
-- This workspace overlays: /opt/ros/kinetic
-- Found PythonInterp: /usr/bin/python2 (found suitable version "2.7.16", minimum required is "2")
-- Using PYTHON_EXECUTABLE: /usr/bin/python2
-- Using Debian Python package layout
-- Using empy: /usr/bin/empy
-- Using CATKIN_ENABLE_TESTING: ON
-- Call enable_testing()
-- Using CATKIN_TEST_RESULTS_DIR: /home/pi/ros_catkin_ws/build_isolated/rospack/test_results
-- Forcing gtest/gmock from source, though one was otherwise available.
-- Found gtest sources under '/usr/src/googletest': gtests will be built
-- Found gmock sources under '/usr/src/googletest': gmock will be built
-- Found PythonInterp: /usr/bin/python2 (found version "2.7.16")
-- Using Python nosetests: /usr/bin/nosetests-2.7
-- catkin 0.7.29
-- BUILD_SHARED_LIBS is on
-- Boost version: 1.67.0
-- Found the following Boost libraries:
--   filesystem
--   program_options
--   system
-- Configuring done
-- Generating done
-- Build files have been written to: /home/pi/ros_catkin_ws/build_isolated/rospack
==> make -j2 in '/home/pi/ros_catkin_ws/build_isolated/rospack'
[ 22%] Building CXX object CMakeFiles/rospack.dir/src/rospack_backcompat.cpp.o
[ 22%] Building CXX object CMakeFiles/rospack.dir/src/rospack.cpp.o
In file included from /home/pi/ros_catkin_ws/src/rospack/src/rospack.cpp:28:0:
/home/pi/ros_catkin_ws/src/rospack/include/rospack/rospack.h:108:39: fatal error: boost/tr1/unordered_set.hpp: No such file or directory
compilation terminated.
make[2]: *** [CMakeFiles/rospack.dir/build.make:63: CMakeFiles/rospack.dir/src/rospack.cpp.o] Error 1
make[2]: *** Waiting for unfinished jobs....
In file included from /home/pi/ros_catkin_ws/src/rospack/src/rospack_backcompat.cpp:29:0:
/home/pi/ros_catkin_ws/src/rospack/include/rospack/rospack.h:108:39: fatal error: boost/tr1/unordered_set.hpp: No such file or directory
compilation terminated.
make[2]: *** [CMakeFiles/rospack.dir/build.make:76: CMakeFiles/rospack.dir/src/rospack_backcompat.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:371: CMakeFiles/rospack.dir/all] Error 2
make: *** [Makefile:141: all] Error 2
<== Failed to process package 'rospack':
  Command '['/opt/ros/kinetic/env.sh', 'make', '-j2']' returned non-zero exit status 2

Reproduce this error by running:
==> cd /home/pi/ros_catkin_ws/build_isolated/rospack && /opt/ros/kinetic/env.sh make -j2