https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70704
--- Comment #25 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Looking at the history of flex, flex 2.5.3 is something pre-1997, then there used to be 2.5.4 and 2.5.4a, and at least RHL updated from the 2.5.4a to 2.5.33 early in 2007, so the question is if there has actually been any official flex releases between 2.5.4a and 2.5.33. I can find tarball with 2.5.33 around, finding something older is already getting harder.
