Building X11R6.8 in Fedora 15 - Flex not found

[Doug Kuvaas]

I am trying to build an older version of X Server on Fedora 15 to
allow me to run a legacy application.  Fedora 8, which functions
correctly for our application, will not install on a new computer for
some reason, presumably because the new hardware uses UEFI, and Fedora
15 does not correctly run the application.

When I try to build X11R6.8 from source, I get the following error
"ld:  cannot find -lfl".  Doing some digging, I found that this error
is because the linker cannot find the flex library, however flex is
installed.  I am running a minimal install of Fedora 15 i686 with the
dev libraries and tools installed, nothing else.

Kernel Version is 2.6.38.6-26.rc1.fc15.i686.PAE

Does anyone have any ideas on how to clear this error?  All the
answers I found just said to install flex.