compat-flex for Fedora
The package compat-flex is provided as a safe default for cases, where
new flex (2.5.33 at the time of this writing) fails to work for some
reason. It is possible to have this package installed alongside flex,
and pick whichever of them you need at the moment.
You need to do the following to compile your project with compat-flex:
+ Process the .l file with either flex-2.5.4a, or flex-2.5.4a++,
depending on whether you want C or C++ scanner.
+ Use -I/usr/include/flex-2.5.4a compilation flag when you use
<FlexLexer.h> header file.
+ Use -L/usr/lib/flex-2.5.4a (or -L/usr/lib64/flex-2.5.4a on 64bits)
linker flag when linking against -lfl.
If the build system supports this, all you need to do is provide the
right values of FLEX, CFLAGS or CPPFLAGS, and LDFLAGS environment