let supported_formats () =
  let standard = ["cudf://";"deb://";"deb://-";"eclipse://"in
  let rpm = 
IFDEF HASRPM THEN
     ["hdlist://";"synthesis://"]
ELSE
     []
END
   in
   let db =
IFDEF HASDB THEN
     ["pgsql://";"sqlite://"]
ELSE
     []
END
   in
   standard@rpm@db