[XeTeX] xdvipdfmx doesn't seem to respect PDF crop areas

[Zachary Pincus]

> In my (very limited) testing so far, it looks OK. If some "early
> adopters" (especially OS X users who can run both xdv2pdf and
> xdvipdfmx and compare results) care to update to the latest code from
> Subversion, and check that the various cases of image and PDF
> placement are handled consistently, that would be appreciated.
I'll bite.

Do I need to just compile the xetex sources from the svn, or do I  
also need to get a new checkout of xdvipdfmx?

I grabbed the svn sources and tried to build with the build-xetex  
script, but that fails with:
build-xetex: line 30: cd: Work/texk/web2c: No such file or directory
build-xetex: line 35: cd: Work/texk/xdv2pdf: No such file or directory
Is there any brief readme for compiling xetex from SVN on OS X? Do I  
need to get some external dependencies like we3b2c and xdv2pdf manually?

Also, can I run xetex from the build dir (or install it into a  
sandbox) and yet have it find the rest of my tex install? Not sure if  
I want to overwrite my current xetex with the bleeding-edge checkout  
just yet.

Sorry for such newbish questions, but I haven't been able to figure  
this all out.

Zach