In my experience, the cross-compiler will refuse to link against shared libraries that "don't exist", which they usually don't in a cross compiler setup (e.g. cross compiling an aarch64 application that uses SDL on a ppc64le host with ppc64le SDL libraries)

The usual workaround, I think, is to use dlopen/dlsym from within the program. This is how the Nim language handles libraries in the general case: at compile time, C imports are converted into a block of dlopen/dl* calls, with compiler options for indicating some (or all) libraries should be passed to the linker instead, either for static or dynamic linking.

Alternatively I think you could "trick" the linker with a stub library just containing the symbol names it wants, but never tried that.