Using layout to assemble a distribution from a local build, --include-html-doc doesn't seem to be doing anything

OK - fifth time lucky. I had four earlier questions but that dang ‘your topic is similar to…’ box found me the solutions before I could post. It’s surprisingly effective.

[edit: the question has changed, because I spotted the --doc-build option to layout, which suggests that I ought first to have done something to cause the docs to get build, so my new question is: “how?” though I’ll keep looking in PCbuild in case an answer suggests itself]

Using help from the ‘Python Help’ forum I’ve done a local Windows x64 build of Python. I wanted to munge it into the shape of Python as created by the installer, and the forum informed me about the layout tool, which is also a bit impressive.

There are still bits missing from my distribution though, when I compare it with the result of running the installer. One of them is the html docs. I was already using python3 -m layout --all, but I added --include-html-doc anyway. The docs still aren’t there though, and to be fair to layout they’re also not in the unpacked source tarball. Maybe they’re generated with pydoc at some point in a build? In case that was it, I looked for suggestive-looking properties in PCbuild/*.props, and came up empty. I think I must be missing something big. Does anyone know what?

Thanks,
Tim

[edit because I’d forgotten that layout is a package, not a single module]