pip install FileNotFoundError: [Errno 2] No such file or directory:

The package is simply broken, as it is missing the setup.py file.

$ tar tzvf behave-parallel-1.2.4a1.tar.gz | grep setup.py
$

You might be able to download the source from Github or wherever and package it yourself (python setup.py bdist_wheel), then install that wheel (pip install ../../dist/behave-parallel...whl).

There is a newer feature for building python packages (see also PEP 517 and PEP 518). A package can now be built without setup.py (with pyproject.toml), but older pip versions are not aware of this feature and raise the error shown in the question.

So if you have reason to believe that the library was packaged properly, try updating pip to something newer (version 19 or newer will probably work).

In my case with the same error, the solution was to do

pip3 install --upgrade pip 

It was my pip3 that was in version 9.X were it's now in version 19.X