buffer overflow when a problem has `hold`

[gqqnbig]

$ cat h.sim
begin
hold(1)
end;
$ cim h
Compiling h.sim:
"h.sim", line 3: *** buffer overflow detected ***: terminated
[1]    2072 IOT instruction (core dumped)  cim h

My program only has three lines; one of them is hold(1). When I compile it, cim throws error "buffer overflow detected".

I'm by no means an expert in Simula, but I insist the compiler shouldn't crash out.

I compiled cim on my machine. Its version is cim-5.1-x86_64-pc-linux-gnu.