Warning: Harfbuzz library versions before 8.0.0 gives rendering/layout issues with font Annapurna SIL (maybe others)

XeTeX uses the harfbuzz library "behind the scenes" in producing the text.
We've identified a problem with the way that Annapurna is handled in harfbuzz versions 7.3.0 and lower, as found in Ubuntu 22.04, and 20.04 and at least some windows machines. Other fonts and scripts may be affected also. The bug seems to result in an under-reporting to XeTeX of how wide some words will be and/or extra or lost spaces, resulting in excursions into the margins, and layout changes. It seems to only be triggered a few times per page (maybe certain words or letter combinations), but the effects on layout can be significant.

The good news for users of ubuntu-based linux distributions is that 24.04 has a significantly updated harfbuzz library which does not show the problem.

[ Edit: it used to be unclear which version between 8.3 and 6.0 had the issue. We now know that harfbuzz 8.0.0 is the first release that does not have the issue.]

It is also possible to compile and install a new harfbuzz version (In tracking down the version I tried with multiple versions of the library on ubuntu 22.04; there are a couple of changes but its not too tricky to build) and installing the relevant .deb packages solves the problem.

Unfortunately, there are various dependencies that make it hard to try compiling a version of harfbuzz without this bug on ubuntu 20.04

Begin with the Annapurna SIL/XeTeX reproduction described for Ubuntu 20.04 and 22.04, comparing HarfBuzz versions before and after 8.0.0. No file, test, entry point, or concrete repository change is named, so the completion criteria remain undefined.