- provision.sh step_runner: actions/runner 2.338.0 (sha256 checked) at /opt/actions-runner under a dedicated user `runner`
(no sudo, not in build's group), rustup 1.99.0 pinned with both targets, sccache against /srv/sccache in READ_ONLY mode
on its own server port, Node 22 and mingw from the system, GitHub's svc.sh unit with a Nice 10 drop-in; registered on
igneum-network/igneum as igneum-build-1 (labels self-hosted, linux, x64, igneum-build-1) through
infra/build-server/runner/register.sh (gh as igneum-josh, the token on ssh stdin, never logged). Idempotent after
the env files moved behind svc.sh install (its env.sh rewrites them). libicu74 and python3-numpy added to APT.
- main's slots ruling: SLOTS default 2; remote-run.sh sets CARGO_BUILD_JOBS 90 when it holds the only taken slot and 45
when both are held, BR_MEASURE=1 takes the `measure` file exclusively and excludes builds (builds hold it shared),
lock files open in append mode (the old `exec {fd}>` truncated a busy slot's holder line on every probe), env
IGNEUM_BUILD_SLOTS_DIR and IGNEUM_BUILD_LOG_DIR win over the profile, `--self-test-slots` with five cases (the old
script fails it with JOBS=none); build-remote.sh and cross-remote.sh pass -j only when --jobs is given.
- infra/build-server/prover/cpu-trial.sh: the SP1 CPU prover on one fixture shard under the measure hold with a VmHWM
poller; 6 Oct 2026 run: core 34.2 s, compressed 85.9 s, peak RSS 28.2 GB on 96 threads, so no standing CPU prover.
- docs/plans/ci-self-hosted.md: the proposed runs-on change for ci.yml behind the repository variable IGNEUM_CI_RUNNER
(GitHub-hosted is the fallback), and why windows.yml cannot move to a Linux box. Workflows untouched.
- docs/plans/build-server.md section 7.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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