it's necessary to require subr-x! also use mapc instead of mapcar

monroe.el

@@ -40,6 +40,7 @@
 
 (require 'comint)
 (require 'cl-macs)
+(require 'subr-x)
 
 (defgroup monroe nil
   "Interaction with the nREPL Server."
@@ -319,10 +320,11 @@ monroe-repl-buffer."
     ;;
     ;; This 'ignore-errors' is a hard hack here since 'accept-process-output' will call filter
     ;; which will be this function causing Emacs to hit max stack size limit.
-    (when (eq ?e (aref string (- (length string) 1)))
-      (unless (accept-process-output process 0.01)
-        (while (> (buffer-size) 1)
-          (mapcar #'monroe-dispatch (monroe-net-decode)))))))
+    (ignore-errors
+        (when (eq ?e (aref string (- (length string) 1)))
+          (unless (accept-process-output process 0.01)
+            (while (> (buffer-size) 1)
+              (mapc #'monroe-dispatch (monroe-net-decode))))))))
 
 (defun monroe-new-session-handler (process)
   "Returns callback that is called when new connection is established."