Well yes, there are several workarounds; to the point that there are packages that wrap up all methods and try to decide which one is the correct one in the given invocation. This is the problem with R - there are many things for which you need only a single line to do something very complicated, but there are also many things that are just a tiny bit different from the standard cases, and are absurdly complex. Everything is just slapped together, without thought for the overall picture or overarching design.

Google stack overflow for 'R get current script path' some time, and weep not only at how often this is asked and upvoted (i.e., how many people suffer from this), but also at the suggestions offered - how divergent they are, and how complicated. But this is just one example. R is death by a thousand cuts.