Why does ALSO usage lead to different results in R2 and R3?

Question

This code returns -1 for R3 and +1 for R2. I'd like to know what I am doing wrong.

 f: func [] [
     also  return  1
           return -1
 ]
 f

Answer 1

You are doing nothing wrong; unfortunately you are tripped up by a known bug in R3. Basically, the also incorrectly "eats up" the return. Fortunately, we have a fix for this forthcoming. (If you want to help with testing, have a look at my fix-unwind-passing branch.) I hope we'll have this fix done and integrated shortly.