> Yes, it's not a good idea to do this. There are more questionable pieces in gnulib, like closing stdin/stdout/stderr (because fflush and fsync is deemed too slow, and regular close reports some errors on NFS on some systems that would otherwise go unreported).

Hyrum's law strikes again. People cast dl_info and poke at internal bits all the time too.

glibc and others should be using kernel-style compiler-driven struct layout randomization to fight it.