Self-hosted runners refuse to start a code review session twice

A self-hosted runner now refuses a code review session another worker has already taken, and its --startup-timeout-min help was reworded

You'll noticeTier: how much it should matter to you

1Useful: my rating, 1 to 5

2Signal: worth watching, 1 to 5

Self-Hosted RunnersArea: what it touches

ImprovementsKind: in v2.1.309, 22 Oct 26

ImprovementsSection of the release

What

A self-hosted runner is a program you run on your own machines to host Claude Code sessions. If a code review session has already been taken by a worker, the runner now refuses to start it again and reports an error, because a code review is started only once.

The help text around --startup-timeout-min has been rewrapped. It lists SELF_HOSTED_RUNNER_SESSION_IDLE_MS as the environment variable for the idle option.

Why

For people running self-hosted runners, this stops one code review from being run twice by different workers.

What the documentation says

--startup-timeout-min Self-hosted environments reference modified, high confidence | `--startup-timeout-min <n>` | `SELF_HOSTED_RUNNER_STARTUP_TIMEOUT_MS` | `15` | Release a session slot if the child hasn't signaled on the [activity channel](/docs/en/self-hosted-environments-configuration.md#keep-stdin-and-file-descripto… see the edit

How sure we are

Two sources agreeTwo things we can check say the same as this entry.

Anthropic's documentation agrees--startup-timeout-min on Self-hosted environments reference

Anthropic's release notes agreeSelf-hosted runner: Fixed --startup-timeout-min stopping a session whose first prompt, such as /code-review, was still working in a…

See this entry in the whole of v2.1.309 →

The build it came inv2.1.309

22 Oct 2026 · 281 entries, this one is #103.

Use it now14
You'll notice167
Nothing to try yet16
Under the hood84

Either side of it

v2.1.308Older

Open the release →

Names in this entry

cli--startup-timeout-min
New flags retire a runner at a set time, release idle sessions, and control drain behaviour.
envSELF_HOSTED_RUNNER_SESSION_IDLE_MS
A self-hosted runner now refuses a code review session another worker has already taken, and its --startup-timeout-min help was reworded

Anthropic's note

Upstream's own release notes for v2.1.309 name something this entry names, so the two are probably about the same change. Probably: the pairing is made on a shared name rather than on the words around it.

Self-hosted runner: Fixed --startup-timeout-min stopping a session whose first prompt, such as /code-review, was still working in a subagent; a frozen process is still stopped

Is this right?