In an org-mode file:
#+BEGIN_SRC haskell let x = "test" putStrLn x #+END_SRC
executing Haskell code block... if: ‘org-babel-script-escape’ expects a string
I didn't manage to comprehend the source code inducing the error, but...
I have same error with
#+BEGIN_SRC haskell :results value :eval (inferior-haskell-start-process)
works for some reason.
haskell-mode 20180601.143 installed org 9.1.13 installed
I've solved it writing the header argument
:results output after the declaration of the language in the head of the block source.
#+BEGIN_SRC haskell :results output