[temac]

Unfortunately _FORTIFY_SOURCE=2 is documented as making some conforming program fail, and it seems hard to find precise informations on this subject, so i'd be hesitant to use it, as well as _FORTIFY_SOURCE=3

[leni536]

FWIW Debian uses _FORTIFY_SOURCE=2 for building its packages for a long time now, so there should be plenty of experience there for using the option.