scalpel returns error for non-empty directory on empty directory

[l0uismustdie]

Hello. I am trying to run scalpel on my MacBook Pro. I have used this program on my Linux machine with no problem, however, when trying this on my Mac I get an error claiming the directory I am trying to output to isn't empty when it is.

Relevant code:

*:scalpel-1.60 ***$ ls -al recovered/
total 0
drwxr-xr-x   2 ***  ***   68 Aug 27 18:16 .
drwxr-xr-x@ 29 ***  ***  986 Aug 27 18:16 ..

*:scalpel-1.60 ***$ ./scalpel / -o recovered/
Scalpel version 1.60
Written by Golden G. Richard III, based on Foremost 0.69.
ERROR: You have attempted to use a non-empty output directory. In order
       to maintain forensic soundness, this is not allowed.
Aborting.

If anyone has any ideas about this I would be very grateful.