I recently had a problem creating LLVMHello.
I used this CMake file
cmake -G "Eclipse CDT4 - Unix Makefiles" -DLLVM_TARGETS_TO_BUILD="X86"
then I ran
and the build failed on an error about LLVMHello.export
The problem turned out to be that the parent directory path had a
space in one of the folder names.
I removed the space and now LLVMHello builds properly.
Hope you find this useful.