* \throws repo::RepoNoUrlException if no urls are available.
* \throws repo::RepoNoAliasException if can't figure an alias
* \throws repo::RepoUnknownTypeException if the metadata is unknown
+ * \throws repo::RepoException if the repository is invalid
+ * (no valid metadata found at any of baseurls)
* \throws Exception on unknown error.
*/
void refreshMetadata( const RepoInfo &info,