/**
   require.s2 module which returns either the repo db
   (specified by the -R|--repo-db=DBFILE script flags)
   or (if that fails)
*/
return requireS2(['fsl/context'], proc(F){
    affirm F.db;
    F.db.repo && return F.db.repo;
    F.db.checkout && return F.db.checkout;
    catch return requireS2(['fsl/db/repo']).0; // fails if no -R|--repo-db=DBFILE flag specified
    return requireS2(['fsl/db/checkout']).0;
});

