Linking different libraries for Debug and Release builds in Cmake on windows?

According to the CMake documentation:

target_link_libraries(<target> [lib1 [lib2 [...]]] [[debug|optimized|general] <lib>] ...)

A "debug", "optimized", or "general" keyword indicates that the library immediately following it is to be used only for the corresponding build configuration.

So you should be able to do this:

add_executable( MyEXE ${SOURCES})

target_link_libraries( MyEXE debug 3PDebugLib)
target_link_libraries( MyEXE optimized 3PReleaseLib)

Somehow the answer from @Mike Willekes got CMake linking in the same target both release and debug for me :(

I only got this working by setting both configurations in one line, as suggested by @sakra in a related question - and doing so for every library that needed to be linked:

target_link_libraries ( app
    debug ${Boost_FILESYSTEM_LIBRARY_DEBUG}
    optimized ${Boost_FILESYSTEM_LIBRARY_RELEASE} )

target_link_libraries ( app
    debug ${Boost_LOG_LIBRARY_DEBUG}
    optimized ${Boost_LOG_LIBRARY_RELEASE} )

target_link_libraries ( app
    debug ${Boost_PROGRAM_OPTIONS_LIBRARY_DEBUG}
    optimized ${Boost_PROGRAM_OPTIONS_LIBRARY_RELEASE} )

# ...

I would like to add a few notes to the previous answers.

If you need to create a list of multiple files you want to link and store that in a cache variable then you need to add the optimized or debug specified before each and every library. This can be especially useful for larger makefiles/projects.

So for example you could do something like this:

set( MyFavLib_LIBRARIES 
    debug debug/module1.lib optimized release/module1.lib
    debug debug/module2.lib optimized release/module2.lib )
target_link_libraries( app ${MyFavLib_LIBRARIES} )