Re: [PATCH v3 6/9] docs: pdfdocs: One-half spacing for CJK translations

Akira Yokosawa [off-list ref] writes:

On Mon, 2 Aug 2021 18:56:16 +0900, Akira Yokosawa wrote:

quoted

CJK documents are much easier to read with a wider baseline stretch.
Applying the onehalfspacing option of "setspace" package looks
reasonable.

Note: \usepackage{setspace} needs to be before that of hyperref in the
preamble.  The 'extrapackages' key (available since Sphinx 2.3) is for
this purpose.

Sphinx versions < 2.3 ignore 'extrapackages' and generate LaTeX
sources without setspace package.
Obviously, building such LaTeX sources will end up in the error of:

    ! Undefined control sequence.
    \kerneldocCJKoff ...exeCJKinactive \singlespacing

Current requirement to build pdfdocs is Sphinx 2.4.4, but LaTeX
sources generated by 1.7.9 can at least be built prior to this change.

Jon, Mauro, do you think this is a regression?

Having the build just fail that way isn't really a good thing...it would
be far better to do the baseline tweaking only with versions of sphinx
that support it or, failing that, to at least refuse to build with a
suitably informative message.

Thanks,

jon