$ export CFLAGS="-march=i486 -mtune=i686 -Os -pipe"
$ export CXXFLAGS="-march=i486 -mtune=i686 -Os -pipe -fno-exceptions -fno-rtti"
$ export PKG_CONFIG_PATH=/usr/lib/pkgconfig:/usr/local/lib/pkgconfig

load sed, m4, bison, make extensions

flex-2.5.35
-----------
$ ./configure --prefix=/usr/local
$ make
$ sudo make install-strip

# cat > /usr/local/bin/lex << "EOF"
> #!/bin/sh
> exec /usr/local/bin/flex -l "$@"
> EOF

$ sudo chmod 755 /usr/local/bin/lex