-elif(NOT EXISTS "${LIBUNWIND_INCLUDE_DIR}/unwind.h")
- message(FATAL_ERROR "libunwind.h was found, but unwind.h was not found in that directory.")
+elseif(NOT EXISTS "${LIBUNWIND_INCLUDE_DIR}/unwind.h")
+ message(WARNING "libunwind.h was found, but unwind.h was not found in that directory.")