While RDEPEND guerds dependencies on X, alsa and cups .. RDEPEND="... X? ( ${CUPS_COMMON_DEP} ${X_COMMON_DEP} ... ) alsa? ( ${ALSA_COMMON_DEP} ) cups? ( ${CUPS_COMMON_DEP} )" .. DEPEND includes them unconditionally: DEPEND="... ${ALSA_COMMON_DEP} ${CUPS_COMMON_DEP} ${X_COMMON_DEP} ... ${X_DEPEND} ..." I would expect consistency about it. What is the intention with it?
This looks like a duplicate of bug #409901. Note that you should disregard my 'or why RDEPEND is even in use' comment in that bug. I was still learning these things back then.
As the very first line preceding those *_COMMON_DEP says, ideally they were optional not only at runtime. Having it be optional at least at runtime was request by several users. If you have further questions let's continue on bug #409901 Richard did mention. *** This bug has been marked as a duplicate of bug 409901 ***