Minimum python version

[i-gianni]

Hello my system python is python 3.6, when I installed ford with pip in a venv I got this error.

Traceback (most recent call last):
  File "/home/i.gianni/libraries/diaglib/.venv/bin/ford", line 8, in <module>
    sys.exit(run())
  File "/home/i.gianni/libraries/diaglib/.venv/lib64/python3.6/site-packages/ford/__init__.py", line 633, in run
    proj_data, proj_docs, md = initialize()
  File "/home/i.gianni/libraries/diaglib/.venv/lib64/python3.6/site-packages/ford/__init__.py", line 236, in initialize
    return parse_arguments(vars(args), proj_docs, directory)
  File "/home/i.gianni/libraries/diaglib/.venv/lib64/python3.6/site-packages/ford/__init__.py", line 513, in parse_arguments
    subprocess.run(command, check=True, capture_output=True, text=True)
  File "/usr/lib64/python3.6/subprocess.py", line 423, in run
    with Popen(*popenargs, **kwargs) as process:
TypeError: __init__() got an unexpected keyword argument 'capture_output'

I guessed it was related to a wrong version of python, so a switched to a conda env with python 3.10 and it worked.
Could you please add to the requirements the minimum version of python that works?

[ZedThree]

We do already have set the minimum required version to 3.8:

ford/pyproject.toml

Line 34 in 6874196

requires-python = ">=3.8"

It's possible the version of pip with python 3.6 is too old to understand that though?

[i-gianni]

Apparently yes, pip installed it without any warning.
Maybe I would still recommend to write it in the README.md ?