first/last return value hangs IPC reply

[demyan]

A function returning (first vec) / (last vec) over IPC never replies — the client blocks forever.

Server:

$ rayforce -p 6630
listening on port 6630
 ...
‣ (set f1 (fn [] (first [10 20 30])))
lambda
‣ (set f2 (fn [] (last [10 20 30])))

Client:

$ rayforce 
 ...
‣ (set h (.ipc.open "127.0.0.1:6630"))
1
‣ (println "%" (.ipc.send h (+ 1 2 )))
3
‣ (println "%" (.ipc.send h (list 'f1)))
<--- hangs
...
‣ (println "%" (.ipc.send h (list 'f2)))
<--- hangs