iOS graphic assets breaking build to device

I am running into an issue similar to this one whenever I build to iPhone, but only if I have images in MyProject/app/assets/iphone. The simulator runs fine with these default icon/splash images in place, and it successfully builds to the device if I remove them. Am I putting them in the wrong place for an alloy project, or is there something else I am missing?

For the record, here is my log output:

[INFO] :   Copying iTunes artwork
[INFO] :   Invoking xcodebuild
[ERROR] :  ** BUILD FAILED **
[ERROR] :  The following build commands failed:
[ERROR] :   CompileC build/MyProject.build/Debug-iphoneos/MyProject-universal.build/Objects-normal/armv7/ApplicationRouting.o Classes/ApplicationRouting.m normal armv7 objective-c com.apple.compilers.llvm.clang.1_0.compiler
[ERROR] :  (1 failure)