Pyinstaller-generated executable fails to find modules in subdir of original script

[eyalroz]

I'm running pyinstaller on a script called foo. In the script's directory, there is a subdirectory named util, and in it is a script named bar.py. In foo, I have:

import os
import sys
sys.path.append(os.path.dirname(os.path.realpath(__file__)))
from utils.bar import func1, func2

# ... etc. ...

after pyinstaller runs and I try running the executable in dist/, I get:

  File "foo/foo.py", line 23, in <module>
ModuleNotFoundError: No module named 'utils'

Of course, the original script itself runs fine.

My question: Is this a pyinstaller bug, or am I doing something wrong?