and it segfaults!
Ew. Shows how much that code is used - in more than two years, nobody
(including me) has noticed the segfault.
Since it's so widely used, and since diving back into environment frame
pushing/popping gives me headaches, I have half a mind to just remove
runblock in the next release (which is a major version bump so
compatibility isn't guaranteed). I'll try fixing the bug for a little
time, and if I can't find it, I'll scrap the whole thing.
I have implemented your -s suggestion in the latest execline git head;
that one was easy. Please test it and tell me if it works for you.