Windows DLL Dependencies/External non-ROS?

edit

I laid out my library in C:\usr\x64 (kind of mirroring ROS on Windows hardcoding to C:\opt\ros\melodic\x64) like this:

C:\USR
└───x64
    ├───include
    │   └───mylib-0.2-rc2
    │       └───mylib
    │               LibName.h
    │
    └───lib
        ├───cmake
        │   └───mylib-0.2-rc2
        │           mylib-config-version.cmake
        │           mylib-config.cmake
        │
        └───mylib-0.2-rc2
                LibName.dll
                LibName.lib

with mylib-config.cmake contents

get_filename_component(PREFIX ${CMAKE_CURRENT_LIST_DIR}/../../.. ABSOLUTE)
set(mylib_INCLUDE_DIRS ${PREFIX}/include/mylib-0.2-rc2)
set(mylib_LIBRARIES ${PREFIX}/lib/mylib-0.2-rc2/LibName.lib)

Pending a better, ROS-correct way to set it, I made a user environment variable CMAKE_PREFIX_PATH with C:\usr\x64. ROS setup.bat files then prepend the ROS paths to that.

Now catkin_make can find my library using find_package(mylib REQUIRED) in my ROS package's CMakeLists.txt.

I'm still having some include issues, so I'm not going to close this question just yet.

[ 39%] Building CXX object mylib_gazebo/CMakeFiles/mylib_hello_node.dir/src/mylib_hello_node.cpp.obj
mylib_hello_node.cpp
C:\usr\x64\include\mylib-0.2-rc2\mylib/LibName.h(5): fatal error C1083: Cannot open include file: 'Eigen/Core': No such file or directory
NMAKE : fatal error U1077: 'C:\PROGRA~2\MICROS~1\2019\COMMUN~1\VC\Tools\MSVC\1427~1.291\bin\Hostx64\x64\cl.exe' : return code '0x2'
Stop.
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.27.29110\bin\HostX64\x64\nmake.exe"' : return code '0x2'
Stop.
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.27.29110\bin\HostX64\x64\nmake.exe"' : return code '0x2'
Stop.
Invoking "nmake" failed

But it's some progress, and I feel like it's a reasonable layout. Is there a correct place to prepend to CMAKE_PREFIX_PATH that's recommended for a ROS workspace?