[wp-testers] Error when upgrading from 2.7.1 to nightly

[Otto]

Got this error. Can't explain it. I check, and the files were correct
on the server, and the _weak_escape function was indeed in the
wp-db.php file.

Fatal error: Call to undefined method WordPress_Module::_weak_escape()
in /home/.../html/blog/wp-includes/wp-db.php on line 473

Ideas?

-Otto