net-im/prosody post install error

[Ross Penner]

When I try to build prosody (on FreeBSD 9.2-RELEASE-p3), I get the
following error once it gets to the installation phase. The error
references already having a prosody user and group. They were created
the first time I tried to install and this message is from my second
attempt.

===>  Installing for prosody-0.9.3
/bin/sh /usr/ports/net-im/prosody/work/pkg-install prosody-0.9.3
PRE-INSTALL
prosody:*:242:
You already have a group "prosody", so I will use it.
pw: user 'prosody' already exists
Adding user "prosody" failed...
*** [pre-install] Error code 1


Thanks for any help or insight you can provide.