Building the RelWithDebInfo configuration of SFML statically using Visual Studio on a CMake-generated solution seems to produce lib filenames without the '-s' suffix. The Release configuration of the same solution does add this suffix. Is it intentional?
I used CMake 3.3.2 on the latest SFML repository with BUILD_SHARED_LIBS=FALSE and SFML_USE_STATIC_STD_LIBS=TRUE, and built with VS 2012.