'artifacts' no longer found on OS/X

Since recently the “artifacts” addon (https://docs.travis-ci.com/user/uploading-artifacts/) does not seem to work anymore on OS/X.

I’m seeing this in the log:

Uploading Artifacts
artifacts.setup
chmod: /Users/travis/bin/artifacts: No such file or directory
/Users/travis/build.sh: line 454: artifacts: command not found

This is on the travis-ci-macos-10.13-xcode9.4.1-1529955246 image.