stap -k --vp 0003 -p4 ....
Systemtap will report the saved temporary directory, and the compiler command line it attempted. Go to the directory to find he main generated file stap_NNNNN_src.c. Force the compiler to produce a preprocessed file with:
make -C /lib/modules/`uname -r`/build M=`pwd` stap_NNNNN_src.i
(note the .i suffix), and the compiler command line should be in the file .stap_NNNNN_src.i.cmd.
stap(1), error::reporting(7stap)