Exit code on exceptions about grenchman HOT 4 OPEN

ᐅ ocamlbuild -use-ocamlfind -lflags -cclib,-lreadline grench.native
+ ocamlfind ocamlc -c -g -annot -thread -package core -package async -package ctypes.foreign -o nrepl.cmo nrepl.ml
File "nrepl.ml", line 1, characters 5-14:
Warning 3: deprecated: module Async.Std
[since 2017-02] use Async. The Std sub-module is no longer needed
File "nrepl.ml", line 2, characters 5-13:
Warning 3: deprecated: module Core.Std
[since 2017-02] Use Core. The Std sub-module is no longer needed
File "nrepl.ml", line 11, characters 21-61:
Warning 3: deprecated: module Core.Std
[since 2017-02] Use Core. The Std sub-module is no longer needed
File "nrepl.ml", line 76, characters 6-13:
Error: This pattern matches values of type 'a option
       but a pattern was expected which matches values of type
         equal:(string -> string -> bool) -> string option
Command exited with code 2.
Compilation unsuccessful after building 7 targets (0 cached) in 00:00:00.