What probably matters to youSection of the release
What
On Windows the self-hosted runner has no default working directory, so --base-dir (or the SELF_HOSTED_RUNNER_BASE_DIR environment variable) must now be supplied; the help text says so. A new launcher_hooks config section is also checked at load: every entry must name a known hook event and point at a .py or .sh filename matching a restricted pattern, and duplicate entries are rejected regardless of letter case.
Details
Config now records whether the base directory came from the built-in default or from SELF_HOSTED_RUNNER_BASE_DIR.
Other platforms keep their existing default base directory.
Evidence
required on Windows, which has no default
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agreeChanged self-hosted runner Windows startup to require an explicit --base-dir; there is no default checkout directory on Windows
