Nataraj S Narayan wrote: > configure: error: Your flex version is too old. Please install flex version > 2.5.33 or newer. > > But my flex installed is of higher version. > > freebsd# make reinstall > ===> Installing for flex-2.5.35_4 Wine checking for particular features (presence of prediluvian.h file) not directly flex version. What it means is that your flex even new version still missing this feature. Contact FreeBSD support/forum and ask where to get full-featured version of flex.