Looking at this part of your back trace:

#
2008-12-18 20:40:52.333 xcodebuild[1070:613] [MT] ASSERTION FAILURE in /SourceCache/DevToolsBase/DevToolsBase-921/pbxcore/FileTypes/PBXCFBundleWrapperFileType.m:174
#
Details: path should be a non-empty string, but it’s an empty string
#
Object:
#
Method: -subpathForWrapperPart:ofPath:withExtraFileProperties:
#
Thread: {name = (null), num = 1}

This implies that something, maybe one of your configuration variables, is blank when it needs to refer to a file. What I’m wondering is if maybe you have an extra target in your project that doesn’t work, so that building with -alltargets is what’s causing your problem.

I tested xcodebuild without any arguments on one of my projects just now – it did a default build of my project without errors. What happens if you try it without arguments?