- self-hosted works technically: outbound HTTPS only, no inbound
ports, honours HTTPS_PROXY/NO_PROXY — a box behind a proxy is fine
- but it defeats the pinned-runner decision: the build host sets the
glibc floor, so a workstation runner (2.39 here) puts it back to
2.38+ and drops Ubuntu 22.04 / Debian 12 / RHEL 9
- and a workstation-built release is unattested
- records what self-hosting accepts: jobs run as the starting user,
with that user's ~/.ssh, credentials and network reach — including
hosts named in ~/.ssh/config; worst on public repos, where a
stranger's PR runs code on the runner
- if unavoidable: dedicated VM, unprivileged user, --ephemeral,
segmented network, treat .credentials as a secret
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>