An error said the O_NONBLOCK symbol with a syntax error!

[gfengyoung]

I install freebsd8, then follow the DevelopersBootStrapAndDevIso on the devwiki, everything is fine before run the command menu.sh
run ./menu.sh
An error  said the O_NONBLOCK symbol with a syntax error!
And It said something wrong with perl.
The building stop for a long time, and I cancel the building
How can I fix it !