pyOCD: Build pyOCD into Single Executable File - file missing in pyyaml

I followed the guide https://github.com/mbedmicro/pyOCD/blob/master/docs/how_to_build.md to build an executable from pyOCD. Before diving into the problem, let’s first list my system settings.  

1. My system

• I work on 64-bit Windows 10
• I’ve got Python 3.8
• I did not set up a virtual environment when starting the procedure, but work directly from my Python 3.8 installation.  

2. The procedure

I issue the following commands in a Windows console:

# We need to use upstream version of pyinstaller due to
# http://comments.gmane.org/gmane.comp.python.pyinstaller/6457
pip install https://github.com/pyinstaller/pyinstaller/archive/develop.zip

# Create single-file executables
pyinstaller --onefile pyocd/tools/gdb_server.py
pyinstaller --onefile pyocd/tools/flash_tool.py
pyinstaller --onefile pyocd/tools/pyocd.py

Everything goes well until the last command:

FileNotFoundError: [Errno 2] No such file or directory:
'c:\\python38\\lib\\site-packages\\pyyaml-5.2b1-py3.8-win-amd64.egg\\EGG-INFO\\top_level.txt'

I check if I’ve got pyyaml properly installed. I run the command pip install pyyaml and everything seems okay:

C:\Seafile\EMBEETLE IDE\pyOCD>pip install pyyaml
    Requirement already satisfied:
    pyyaml in c:\python38\lib\site-packages\pyyaml-5.2b1-py3.8-win-amd64.egg (5.2b1)

 

3. Solution

I believe I found a solution. I created the file top_level.txt myself in the right place:

After googling the keywords yaml and top_level.txt, I discovered that this file should have only two lines:

_yaml
yaml

I issue again the failed command:

$ pyinstaller --onefile pyocd/tools/pyocd.py

Now it works! At least - the compilation works.  

4. Problem with the executable

Unfortunately, the executable itself doesn’t work. I get import errors:

C:\Seafile\EMBEETLE IDE\pyOCD\dist>pyocd.exe --version
    Traceback (most recent call last):
      File "pyocd\tools\pyocd.py", line 35, in <module>
    ImportError: attempted relative import with no known parent package
    [7508] Failed to execute script pyocd