In general, the source tree is not assumed to be writeable, so modifying `%s` does not work for all CI systems. Instead of touching `%s`, copy it to a writeable dir using `%t`, and touch it there. Actually, `dr0xx.c` isn't really needed at all, so just create a new `dep.c` file in the build tree. This was recently added incb088e8c3a, fixed in1481fcf780, and fixed again ind16c590130.