Haskell Support Not Working

[gleachkr]

Issue description

• Brief description: Haskell support doesn't seem to be working.
• Expected results: I type a haskell expression, like 1 into a codi haskell buffer, I see the value of the expression, e.g. 1.
• Actual results: I type a haskell expression like 1 into a codi haskell buffer, I see nothing.
• A minimal .vimrc that will reproduce the issue

call plug#begin('~/.config/nvim/plugged')
Plug 'metakirby5/codi.vim'
call plug#end()

• Exact steps to reproduce the issue, starting with the command used to open
  nvim
:Codi haskell
1

Environment

• Operating system: arch linux
• Version of script: script from util-linux 2.36.2
• The following in a pastebin, to reduce visual clutter:
  https://paste.sr.ht/~gleachkr/3a876e7c0cf9f4c51b1ab69300e0fd0a43ca9876

Note: There's a double 1 on the final line of the log output. The evaluated expression always appears, postfixed to the final line of the log, but isn't output on the nvim side.

[rafpaf]

Same with elixir on Ubuntu 20.04, script from util-linux 2.34, NVIM v0.8.0-dev+391-gc5720c722.