#273 tried to fix the macOS Keychain -25308 error by pointing
DOCKER_CONFIG at a per-run temp dir with `{"auths": {}}`. That was
necessary but not sufficient: Docker on macOS inherits `osxkeychain` as
the default credsStore even when config.json doesn't declare one
(comes from Docker Desktop's bundled binding), so the login-action
still tried to call /usr/local/bin/docker-credential-osxkeychain which
fails with -25308 from the non-interactive launchd session.
Evidence: after #273, publish-platform-image still failed on every
main merge with:
error saving credentials: error storing credentials - err: exit
status 1, out: `User interaction is not allowed. (-25308)`
Fix: write a config.json that explicitly sets `credsStore: ""` and
clears `credHelpers`, forcing Docker to store creds in the inline
`auths` map of this disposable config.json instead of reaching for
the keychain. Also print config.json at diagnostic time so a future
regression surfaces in the log instead of at login.
No runtime / test impact — this only changes what the runner writes
to the workflow's temp DOCKER_CONFIG directory.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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