The .hgguestrepo file defines guests by specifying three things:
* location: The location of the guest relative to the root of the parent
+ repository. A path outside the root is allowed if a .grauth file exists
+ in any parent directory of the intended location.
* remote id: The name of a remote path defined in the .hggrmapping file.
* changeset id: A Mercurial identifier e.g., a tag, bookmark, changeset
hash, branch, or other future identifier resolvable to a
Update each guest repo to the changeset identifier in the .hgguestrepo file.
The changeset identifier can be a branch, tag, changeset hex, bookmark, or