Automation: nightly + stable release chain (Aug 2026)

[beakthoven]

What is automated now

Step	How
Upstream version bumps	tc-build Check for Updates daily PR (versions.conf)
Stable toolchain builds	tc-build pipelines, manual dispatch (release tags llvm-*, sysroot-avr-*, bfd-*)
Nightly toolchain builds	tc-build pipelines, daily 00:00 UTC from git HEAD (LLVM main, avr-libc main; libgcc pinned to GCC release). Tags nightly-*
Nightly platform	core_arduino_avr, daily 00:30 UTC, prerelease nightly-<date>
Stable platform	core_arduino_avr: push a semver tag → packaged release
Board manager indexes	BoardManagerFiles update-index.yml on repository_dispatch from the two repos above, daily 06:00 UTC fallback, or manual

Indexes:

• stable: package_clangbuiltarduino_index.json
• nightly: package_clangbuiltarduino_nightly_index.json

One remaining manual step

Add org secret CBA_DISPATCH_TOKEN (classic PAT with repo scope) so tc-build and core_arduino_avr can send repository_dispatch to BoardManagerFiles. Until then the 06:00 UTC fallback cron keeps the indexes fresh.

Known gaps

• llvm-22.1.6-31052026 release shipped without the LLVMgold archive; the index updater pairs clang+gold from the same release and currently serves 22.1.4-26042026. A fresh stable pipeline run (LLVM 22.1.8) fixes this.
• Old nightly releases accumulate in tc-build; add a retention policy if it becomes noise.