Failure to build VT+checkpoint+detector in TPL directory in app

[lifflander]

Describe the bug

20:17:27  -- Configuring done
20:17:28  CMake Error: install(EXPORT "EMPIRE-targets" ...) includes target "input_deck" which requires target "checkpoint" that is not in this export set, but in multiple other export sets: cmake/checkpointTargets.cmake, cmake/vtTargets.cmake.
20:17:28  An exported target cannot depend upon another target which is exported multiple times. Consider consolidating the exports of the "checkpoint" target to a single export.
20:17:28  CMake Error: install(EXPORT "EMPIRE-targets" ...) includes target "RandomNumberGenerator" which requires target "checkpoint" that is not in this export set, but in multiple other export sets: cmake/checkpointTargets.cmake, cmake/vtTargets.cmake.
20:17:28  An exported target cannot depend upon another target which is exported multiple times. Consider consolidating the exports of the "checkpoint" target to a single export.
20:17:28  CMake Error: install(EXPORT "EMPIRE-targets" ...) includes target "utils" which requires target "checkpoint" that is not in this export set, but in multiple other export sets: cmake/checkpointTargets.cmake, cmake/vtTargets.cmake.
20:17:28  An exported target cannot depend upon another target which is exported multiple times. Consider consolidating the exports of the "checkpoint" target to a single export.
20:17:28  -- Generating done
20:17:28  CMake Generate step failed.  Build files cannot be regenerated correctly.

[PhilMiller]

This alone doesn't fix it