Host git only fetches into bare mirrors no sandbox ever sees, https only, with no user or system config and overrides emptying hooks, fsmonitor, ssh and proxy commands and every filter driver the mirror defines. Each build is a git archive of the commit and of each submodule commit from its own mirror. Old working-tree clones are deleted. The core copied out must be a regular file inside the build folder, opened without following links.
make runs on a git archive export of the commit and its submodules, the clone and its .git never bound into the sandbox. Host-side git runs with no user or system config, no hooks, no fsmonitor and the file and ext transports refused.
Without a working bubblewrap the pass is refused and nothing third-party runs, probes require the sandbox and builds are refused, unless --allow-unsandboxed is given. A job report holding an alert raises an autorun alert.
core_probe starts its worker with only the --env values, the worker clears its own environment before loading the core, and a working bubblewrap runs it with a read-only tree, no network and the user's credentials masked. The record names the isolation used. A timeout kills the whole process group. campaign.py starts core_probe, git, make and romfetch with the allowlist, make inside the same sandbox. --record refuses a folder that is not a checkout root.
campaign.py takes buildbot nightlies (or a build of the pinned commit), the test content of tests/campaign/content.yml through romfetch, and runs core_probe for the files, boot, path, alias, variants and bench checks. A fixed rule table settles hle_fallback, required, path and aliases with the record ids as evidence, the rest goes to measurements/findings.jsonl. Resumable state, load, disk and budget guards, retries, content reference counting with an LRU cap, and an autorun job after the nightly.
Abdessamad Derraz