Function lower_packages_selecting 

pub fn lower_packages_selecting(
    packages: &[(String, Package)],
    selection: &Selection,
    external: &ExternalPackages,
) -> (Crate, Vec<SkippedType>)

The same, from packages already decoded rather than from a DAR.

A DAR is one way to get packages; a participant is another, and often the better one — AdminClient::get_package returns exactly what a participant has vetted, whereas a DAR file has to be found somewhere and may not exist for a package that is nonetheless live on the network. A package id is the hash of its own bytes, so a set assembled this way is pinned by its ids.

Errors

This cannot fail: the packages are already decoded. It returns the same pair as lower_dar_selecting so the two read alike at a call site.