As I mentioned, I can't reproduce your error (Python 3.7 with modern pip seems to work just fine), but there are a couple things that could potentially be going wrong on older versions.

Since it doesn't look like you put __init__.py files in your subdirectories, find_packages doesn't actually find any packages at all (python3 -c 'from setuptools import find_packages; print(find_packages()) prints the empty list, []). You can fix this in one of three ways:

1. Create empty __init__.py files to explicitly mark those folders as package folders; on a UNIX-like system, touch jkt/__init__.py and touch jkt/scripts/__init__.py is enough to create them
2. Python 3.3+ only: (also requires modern setuptools so pip install --upgrade setuptools might be necessary) Replace your use of find_packages with find_namespace_packages (which recognizes Python 3 era implicit namespace packages).
3. Just get rid of find_packages entirely and list the packages directly, e.g. replace packages=find_packages(), with packages=['jkt', 'jkt.scripts'],

Options #2 only works on Python 3.3+, so if your package is intended to work on older versions of Python, go with option #1 or #2.

As I mentioned, I can't reproduce your error (Python 3.7 with modern pip seems to work just fine), but there are a couple things that could potentially be going wrong on older versions.

Since it doesn't look like you put __init__.py files in your subdirectories, find_packages doesn't actually find any packages at all (python3 -c 'from setuptools import find_packages; print(find_packages()) prints the empty list, []). You can fix this in one of three ways:

1. Create empty __init__.py files to explicitly mark those folders as package folders; on a UNIX-like system, touch jkt/__init__.py and touch jkt/scripts/__init__.py is enough to create them
2. Python 3.3+ only: (also requires modern setuptools so pip install --upgrade setuptools might be necessary) Replace your use of find_packages with find_namespace_packages (which recognizes Python 3 era implicit namespace packages).
3. Just get rid of find_packages entirely and list the packages directly, e.g. replace packages=find_packages(), with packages=['jkt', 'jkt.scripts'],

Options #2 only works on Python 3.3+, so if your package is intended to work on older versions of Python, go with option #1 or #3.