GHCi 8.6.3 hangs and is impossible to kill after `nub $ cycle "a"`
When I open GHCi (version 8.6.3) and type
import Data.List
nub $ cycle "a"
The REPL completely freezes. I cannot even kill it with C-c
, SIGTERM. After killing the whole terminal, the process is still present and eats 100% of a single CPU core. I couldn't find different way to stop it than smashing it with SIGKILL. If I omit the nub
everything works as expected – the computation obediently terminates after hitting C-c
.
Is it desired behavior or is it a bug?
I am using Arch Linux with kernel 5.0
on x86_64 CPU