re-adding paragraph

Author: torri

docs/using_eessi/building_on_eessi.md

@@ -205,5 +205,7 @@ Hello World from rank 1
     RPATH should never point to a compatibility layer directory, only to software layer ones, as all resolving is done via the runtime linker (`ld-linux*.so`)
     that is shipped with EESSI, which automatically searches these locations.
 
+The biggest downside of this approach is that your executable becomes bound to the architecture you linked your libraries for, i.e., if you add to your executable RPATH a `libhdf5.so`compiled for `intel_avx512`, you will not be able to run that binary on a machine with a different architecture. If this is an issue for you, you should look into how EESSI itself organises the location of binaries and perhaps leverage the relevant environment variables (e.g., `EESSI_SOFTWARE_SUBDIR`).
+