cygwin下安装gcc

[北燕fly]

when I install gcc,undefiend reference to _lexer_line,yyend...
when I install flex,undefiend reference to "_yylex"
I have installed :
Cygwin Package Information
Package Version Status
ash 20040127-3 OK
autoconf 4-1 OK
automake 2-1 OK
base-files 3.7-1 OK
base-passwd 2.2-1 OK
bash 3.2.25-17 OK
binutils 20060817-1 OK
bison 2.3-1 OK
bzip2 1.0.3-2 OK
coreutils 6.9-5 OK
$
cygutils 1.3.2-1 OK
cygwin 1.5.25-5 OK
diffutils 2.8.7-1 OK
editrights 1.01-2 OK
expat 1.95.8-2 OK
file 4.21-1 OK
findutils 4.3.11-1 OK
gawk 3.1.6-1 OK
gcc 3.4.4-3 OK
gcc-core 3.4.4-3 OK
gcc-g++ 3.4.4-3 OK
gcc-testsuite 3.4.4-3 OK
gdb 20060706-2 OK
gdbm 1.8.3-8 OK
gettext 0.15-1 OK
grep 2.5.1a-4 OK
gzip 1.3.12-2 OK
libbz2_0 1.0.2-1 OK
libcharset1 1.11-1 OK
libexpat0 1.95.8-2 OK
libgdbm 1.8.0-5 OK
libgdbm-devel 1.8.3-7 OK
libgdbm3 1.8.3-3 OK
libgdbm4 1.8.3-8 OK
libiconv 1.11-1 OK
libiconv2 1.11-1 OK
libintl1 0.10.40-1 OK
libintl2 0.12.1-3 OK
libintl3 0.14.5-1 OK
libintl8 0.15-1 OK
libncurses7 5.3-4 OK
libncurses8 5.5-3 OK
libpcre0 7.2-1 OK
libreadline5 4.3-5 OK
libreadline6 5.2.7-9 OK
login 1.9-7 OK
m4 1.4.10-1 OK
make 3.80-1 OK
man 1.6e-1 OK
ncurses 5.5-3 OK
patch 2.5.8-9 OK
pcre 7.2-1 OK
perl 5.8.8-4 OK
readline 5.2.7-9 OK
sed 4.1.5-2 OK
tar 1.19-1 OK
tcltk 20060202-1 OK
termcap 20050421-1 OK
terminfo 5.5_20061104-1 OK
texinfo 4.8a-1 OK
vim 7.1-1 OK
w32api 3.10-1 OK
which 1.7-1 OK
zlib 1.2.3-2 OK