Fix extras_require specification

[mweinelt]

Otherwise setuptools will now error out with

setuptools.extern.packaging.markers.InvalidMarker: Expected a marker variable or quoted string

[git-developer]

@JelmerT This issue currently prevents building an up-to-date Docker image.

The culprit is the empty key in '': ["intelhex"],. Removing the line as proposed in this PR is one option. I see alternatives, though.

As far as I understand from setup.py:

• intelhex is an optional dependency
• python-magic is an optional dependency of intelhex
• intelhex is installed by default; python-magic is not installed by default.

If I understand setuptools#1139 and a discussion about Adding a default extra_require environment right, setuptools doesn't support a dependency that is both optional and installed by default. Thus, I see the following options:

1. Make intelhex a hard requirement, so that users get intelhex automatically and cannot skip it:

   install_requires=["pyserial", "intelhex"]
   

2. Do not install intelhex by default so that users explicitely declare the desired dependency by installing one of cc2538-bsl or cc2538-bsl[intelhex] or cc2538-bsl[python-magic]:

   extras_require={
       'intelhex': ["intelhex"],
       'python-magic': ["intelhex", "python-magic"]
   }
   

What do you think?

[JelmerT]

@mweinelt @git-developer did #159 fix this? I think it's now an in-between your 2 options solution?

[mweinelt]

Looks good to me.

[git-developer]

Fixes the broken build, but the behavior is a little bit strange because

• requirement intelhex triggers package python-magic and
• requirement cc2538-bsl triggers package intelhex:

$ pip3 install 'cc2538-bsl @ git+https://github.com/JelmerT/cc2538-bsl'
[…]
Installing collected packages: pyserial, cc2538-bsl

$ pip3 install 'cc2538-bsl[intelhex] @ git+https://github.com/JelmerT/cc2538-bsl'
[…]
Installing collected packages: pyserial, python-magic, cc2538-bsl

$ pip3 install 'cc2538-bsl[cc2538-bsl,intelhex] @ git+https://github.com/JelmerT/cc2538-bsl'
[…]
Installing collected packages: pyserial, intelhex, python-magic, cc2538-bsl

I prefer option 2 from above (I can open a PR if you agree).

[Szewcson]

I agree with @git-developer. His proposition seems better then my hotfix. I was focused mainly on fixing issue with missing pyproject.toml and making package installable.