I need to build a specific release of Zimbra, for instance 8.0.0_GA_5434

I set up p4 with:

P4PORT=codes.zimbra.com:2666
P4USER=public
P4PASSWD=public1234
P4CLIENT=public-view

and indeed it can checkout //depot/zcs/IRONMAIDEN/...

But how can I list the available branches?
'p4 branches' gives no output, is it a permission problem?

I tried using IRONMAIDEN-5434 as mentioned in [ https://wiki.zimbra.com/wiki/Buildin...using_Perforce ]
but nothing is there.

Thanks.