Ref string `json:",omitempty"`

	// If RepoSum is non-empty, then the resolution of this module version
	// failed due to the repo being available but the version not being present.
	// This depends on the entire state of the repo, which RepoSum summarizes.
	// For Git, this is a hash of all the refs and their hashes.
	RepoSum string `json:",omitempty"`
}