Add pass-through of sphinx-build CLI arguments to make.bat.new_t

[bskinn]

Is your feature request related to a problem? Please describe.

It's frustrating not being able to pass extra arguments to make.bat that then get provided to sphinx-build. E.g., > make html -Ean is not feasible. (This is a subset of #3741.)

Describe the solution you'd like

I'd like this capability to be added to Sphinx. I already have an implementation in my fork.

Describe alternatives you've considered

#3841 attempted a more-ambitious implementation, but was rejected due to likely too-great maintenance requirements. It looks like the whole makefile/make.bat setup will be obsoleted by #5618; but this seems like a simple enhancement to implement in the meantime.

Additional context

Screencap of implemented feature in action:

[tk0miya]

make.bat already provides an environment variable %SPHINXOPTS% to give extra option on execution. I think this would help your case. Please try it :-)
https://www.sphinx-doc.org/en/master/man/sphinx-build.html#environment-variables

[bskinn]

Yes, I know of %SPHINXOPTS already. Using an env variable for this purpose is awkward and slow, because I rarely want to use the same sphinx-build options in consecutive invocations, and as far as I know there's no elegant/quick way to tweak the environment for a particular shell command.

On Linux, make html O={options} works nicely, but I have not been able to get anything like that to work on Windows. If it does work somehow, and I've just been doing it wrong, then introducing the same %O% (or similar) shorthand variable as in Makefile would be most convenient. Then at least something terse like > set O=-E -a & make html should work ok.

[tk0miya]

Thank you for explanation. I understand your goal. But, personally, I feel a bit strange for giving parameters for sphinx-build as arguments of make.bat. I know windows is not under UNIX culture. But...

Note: I'm okay to add %O% shorthand to make.bat. But it would not resolve your concern.

[bskinn]

I feel a bit strange for giving parameters for sphinx-build as arguments of make.bat.

Ahh, I hadn't thought of it from that angle -- yeah, make doesn't pass arguments through, so it would be odd for make.bat to do so.

I can open a PR to add the %O% shorthand option to make.bat--that at least will reduce the amount of typing necessary to adjust the build arguments. Which branch should I take out the PR against... probably 2.0, since this shouldn't be a breaking change?

[tk0miya]

@bskinn I think %O% does not break compatibility. So 2.0 branch is better for this. Could you send a PR please?