GHA: build docs from BOOST_ROOT

[sdarwin]

Hi,
I have some scripts that build each boost library's documentation individually, to test they are working as expected. (Those scripts are in release-tools/build_docs).

For all other boost libraries, this technique works:

cd $BOOST_ROOT
./b2 _path_to_library_docs_

boostorg/geometry is an exception. This pull request demonstrates that. Would you be able to decipher why it happens and adjust the process?

Notice that even the "Build examples" job follows this pattern.

cd $BOOST_ROOT
./b2 _path_to_examples_

With earlier versions of geometry, I was implementing a hack, that probably wasn't ideal.

• Manually run ./b2 $librarypath/doc/src/docutils/tools/doxygen_xml2qbk
• That built dist/bin/doxygen_xml2qbk which I added to PATH, so it could be discovered.

It solved the problem temporarily. Now the hack is not working either, but a more official solution is preferable, anyway.

[barendgehrels]

Thanks @sdarwin
I didn't look in detail yet, but the CI fails on this PR. This means it's not backwards compatible. How can that be fixed?

[sdarwin]

@barendgehrels this is both an issue and a pull request.

The geometry docs are not building in the same way that other boost libraries do. The CI failure here demonstrates that.

./b2 _path_to_library_docs_

should work, but it doesn't.

[barendgehrels]

@barendgehrels this is both an issue and a pull request.

OK I see. So it proves the CI doesn't work. But it gets a bit a difficult state now. Because it's not an issue (because a PR) and the PR itself is not good.

@vissarion any idea how we can solve this?

[barendgehrels]

Prevent merge