Hi,
rebuild-pages script work fine for small blogs.
but when a blog has more than 40+ entries, I got error
$ perl ./tools/rebuild-pages --user=**** --pass=***** --blog_id=28
rebuilding (my blog ...
Category built success.
Page built success.
Can't locate object method "AdminScript" via package "MT" at ./tools/rebuild-pages line 164.
thanks in advance.
Reported on Movable Type 5

You may like to open a bug case for this.
http://bugs.movabletype.org/
I've encountered a similar issue and I had to change a bit the rebuild-pages script to make it work.
Kind Regards,
Mihai Bocsaru
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I changed this line in the rebuild-pages script
$url = "http://$hostname/$script_path/" . $mt->AdminScript . "?" . $url;
to this one
$url = "http://$hostname$script_path" . "mt.cgi" . "?" . $url;
Problem solved (I suspect the change to mt.cgi was unnecessary). Apparently, the problem was that $scipt_path is defined as /mt/, which generated //mt// in the URL. Someone down the pipe didn't like it.