Look at the pre-cq rejections on for instance https://chromium-review.googlesource.com/#/c/chromiumos/overlays/chromiumos-overlay/+/965578/

They read as

The following build(s) failed:

betty-pre-cq: The AndroidMetadata stage failed: return code: 1; command: /b/c/cbuild/repository/chromite/bin/cros_sdk -- emerge-betty -p --cols --quiet --root /var/empty -e virtual/target-os

The following keyword changes are necessary to proceed:
 (see "package.accept_keywords" in the p in http://cros-goldeneye/chromeos/healthmonitoring/buildDetails?buildbucketId=8951936939419564976

Your change may have caused this failure. There are also other changes that may be at fault: CL:961666

Commit queue documentation: http://www.chromium.org/developers/tree-sheriffs/sheriff-details-chromium-os/commit-queue-overview



In particular, the error message in the failure has been stuck directly to the build URL, without a newline.