In community/nexuiz 2.5.2-1:
The PKGBUILD currently uses a patch (nexuiz-libjpeg-fix.patch) to add libjpeg7 support, as the engine tries to use libjpeg6 when compiled with the default make options.
The makefile supports an option to allow libjpeg7:

(from the lead Nexuiz developer)
<div0> DarkPlaces has its own copy of the libjpeg defines
<div0> this is so especially windows users can compile DP without manually getting hold of all the dev packages
<div0> because of this DP doesn't link to it the normal way, but dlopens libjpeg
<div0> the option DP_LINK_TO_LIBJPEG basically changes that method to the regular include-and-link
<div0> but then you MUST have libjpeg to compile DP, while normally you can compile DP without having the jpeg library installed
<div0> the DP_LINK_TO_LIBJPEG option was specifically made to support jpeg7 systems

Using this option in the PKGBUILD would remove the need for a patch, but would add libjpeg as a make-dependency.