I have a requirements.txt file that gets looped through to install all of my python packages. All of my packages are fine except for text-diff for some reason. For that package i get a no matching distribution found error. I tried the same command on my local command prompt with no error.
Command in DockerFile: RUN pip3 install -r /usr/bin/requirements.txt
If you have a newer or older python version inside the container, it is possible that text-diff does not support that version so pip cannot find matching distribution for that specific Python version. Try to run a container from the image you used as a base image in the Dockerfile and install the latest text-diff without requirements.txt to see if it works.
If you used pip3 as you wrote in your first post, it should not matter if the default python version in the container is Python 2 and not 3.
As long as you use the pip3 command, it should use Python3. Try with different containers instead of downgrading on the host. And use this syntax instead of using pip3 directly: