Repo attempts to download a prepackaged bundle file to bootstrap each git prior to downloading the most recent data via Git’s HTTP protocol. The latter is more expensive on the server side and results in worse performance so the bundle file allows the download to cut some corners. If a bundle file isn’t available (like in this case), Repo will ignore it and proceed anyway. In other words, don’t pay any attention to this.
In newer versions of repo, this can be ignored using the --no-clone-bundle option, such as:
repo sync --no-clone-bundle