physfs provides CMake targets:

    find_package(PhysFS CONFIG REQUIRED)
    target_link_libraries(main PRIVATE $<IF:$<TARGET_EXISTS:PhysFS::PhysFS>,PhysFS::PhysFS,PhysFS::PhysFS-static>)

physfs is compatible with built-in CMake targets:

    find_package(PhysFS REQUIRED)
    target_include_directories(main PRIVATE ${PHYSFS_INCLUDE_DIR})
    target_link_libraries(main PRIVATE ${PHYSFS_LIBRARY})