Excerpts from Ng Oon-Ee's message of 2010-07-28 04:13:04 +0200:
AUR has the package celt which I've always had installed (installed it long time back to compile some audio app). http://aur.archlinux.org/packages.php?ID=27117
Repos have celt-0.7 which provides celt.
Thing is, when I try to makepkg jack-audio-connection-kit-mp (which doesn't depend on celt at all) it fails when celt is installed, but works when celt-0.7 or no celt is installed.
There's overlap between AUR packages and other stuff here, so I'm not sure whether this belongs on this ML, or even in a personal email to the maintainer. In which case, my question would be, which maintainer?
You can try to explicitly disable celt support. Celt is only needed for netjack to work over the internet. It should be possible to build jack with netjack support but without celt, in which case it would only work in a LAN. If that is not possible, then this is actually a upstream bug.