should we have CMAKE_SKIP_RPATH TRUE ?

just renamed the issue with madebr comment:

The tests are linked against the correct library, but the tests inside the build directory don't have their run path set:

Line 97 in 9e1afdf

set(CMAKE_SKIP_RPATH TRUE)

I think that line should not be there.
CMake will remove the run path when installing the files.

yes, sorry, obviously wrong reporting :) sdl2-compat builds the libSDL2 ... I just need to set the correct LD_LIBRARY_PATH

I leave this opened for your remark about RPATH, @madebr, if this needs to be solved.

set(CMAKE_SKIP_RPATH TRUE) has been removed in cabf98a.