This was useful in pointing out some cross-platform incompatibilities. I may check cibuildwheel as well later to ensure bundling is working correctly.

The failing test is a relatively recent one; I will have to check if that is from here or the FreeType change.

Do you envision that raqm will become the sole text layout method, or do you plan to keep the old manual layouting around (perhaps togglable)? I just noticed that the old layouting method appears to be missing handling of lsb_delta and rsb_delta (see note at https://freetype.org/freetype2/docs/reference/ft2-glyph_retrieval.html#ft_glyphslotrec ("If you use strong auto-hinting, you must apply these delta values! Otherwise you will experience far too large inter-glyph spacing at small rendering sizes in most cases.")) but raqm would likely (hopefully?) take care of that for us. If the manual layouting is going to stay then I'll open a separate issue to implement this (perhaps also to be folded into the FreeType update mega-PR); if not, perhaps we can just forget about it.

I intend for it to replace everything, I think. I have some in-progress work to apply it to PDF/PS/SVG as well.

I did notice the lsb_delta/rsb_delta note and tried to implement it in #29816, though IIRC not much (or even nothing) changed, but I could be misremembering.