Linuxにしか対応してないそうだ

Un*x

http://paco.sourceforge.net/doc/README

Supported architectures and operative systems
=============================================

Paco has been successfully tested on the following platforms:

-------------------------------
OS Version Architectures
-------------------------------
Linux 2.6 x86, x86_64

--> your system here!
-------------------------------

Note:
Paco does not work on systems in which binaries are linked statically, like
FreeBSD or OpenBSD.

まっとうなFreeBSDユーザならportsとかいいそうだけどレンタルサーバ上で使ってるだけなので容量的にports無理だしな。まあFreeBSDへの対応は遠いだろうな。