Python Issues on master baseline

[Rick VanderWal]

Good Morning,

I just did a git pull on the rtems-source-builder repository and I am 
now getting the following error when I execute:

../source-builder/sb-check

Traceback (most recent call last):
   File "../source-builder/sb-check", line 23, in <module>
     import sb.check
ImportError: No module named sb.check

I have also tried running:

../source-builder/sb-set-builder --list-bsets

and get:

Incorrect Source Builder installation

It appears to be an issue the Python module imports. (I'm not very 
familiar with python) After some Googling, I've tried putting an 
__init__.py in the sb directory. Running sb-check now, I get:

error: failed to load Linux host support

This was all done on Ubuntu Desktop 18.04 LTS. Python version is 2.7.17. 
I also tried modifying the sb-check script to force it to run python3 
(Version 3.6.9) and removed the __init__.py file, which also gave:

error: failed to load Linux host support

Adding the __init__.py file back had no effect.

It appears that the last commit on the repository changed how python was 
executed, but I'm not sure if I have a python configuration issue on my 
machine that just doesn't work with it.

Any guidance is definitely appreciated!

-Rick