1. A method for distributed detection of encoded data slices that require rebuilding within a dispersed storage network (DSN), the method comprises: determining to perform a rebuild scanning function for a virtual memory vault, wherein the virtual memory vault has a DSN address range that is divided into multiple DSN address sub-ranges, wherein a plurality of storage units support the virtual memory vault, wherein each of the plurality of storage units is associated with at least one of the multiple DSN address sub-ranges, and wherein a data segment of a data object is dispersed storage error encoded to produce a set of encoded data slices; in accordance with a rebuild scanning functionality allocation mapping: initiating, by a first rebuild scanning agent module of a first device of the DSN, a rebuilding scanning function for a first group of DSN address sub-ranges; processing, by the first rebuild scanning agent module, first rebuild responses to the rebuilding scanning function to produce a first list of encoded data slices for rebuilding; initiating, by a second rebuild scanning agent module of a second device of the DSN, the rebuilding scanning function for a second group of DSN address sub-ranges; and processing, by the second rebuild scanning agent module, second rebuild responses to the rebuilding scanning function to produce a second list of encoded data slices for rebuilding; and queuing, in a rebuild queue, the first and second lists of encoded data slices for rebuilding.