Installing ORBit on Solaris 8

[steve_wong macroview com hk (Steve Wong)]

	Have anyone encountered that and know how to solve it??
	I am currently compiling ORBit 0.5.7 on Solaris 8.
	When I run configure, it finishes successfully but with the following
WARNING.

Flex installed: no

 -----------------------------------------------------------
    WARNING: flex was not found.  Either use the lexer.c
    that comes with the official distribution or install
    flex if you want to regenerate lexer.c from lexer.l.
 -----------------------------------------------------------

	When I run make, it dies and gives the following

gcc -g -O2 -o .libs/tstidl tstidl.o
.libs/libIDL.so -L/usr/local/lib -lglib -L/
sr/local/lib -lglib -R/usr/local/lib
Undefined                       first referenced
 symbol                             in file
__IDL_lex_cleanup                   .libs/libIDL.so
__IDL_prev_token_line               .libs/libIDL.so
__IDL_in                            .libs/libIDL.so
__IDL_lex_init                      .libs/libIDL.so
__IDL_cur_token_line                .libs/libIDL.so
__IDL_lex                           .libs/libIDL.so
ld: fatal: Symbol referencing errors. No output written to .libs/tstidl
collect2: ld returned 1 exit status
make[2]: *** [tstidl] Error 1
make[2]: Leaving directory `/tmp/ORBit-0.5.7/libIDL'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/tmp/ORBit-0.5.7'
make: *** [all-recursive-am] Error 2

I have search the list archive but can't find the answer, can anyone point
me to one if there is any?
I have installed GNU make 3.79.1
		GNU glib-1.2.10
		flex-2.5.4a
		index-2.2.5

It is strange that I have installed flex but the configure said no.
So I doubt that the compilation failure is due to this.