Function cargo::core::resolver::check_duplicate_pkgs_in_lockfile

fn check_duplicate_pkgs_in_lockfile(resolve: &Resolve) -> CargoResult<()>

Checks that packages are unique when written to lock file.

When writing package ID’s to lock file, we apply lossy encoding. In particular, we don’t store paths of path dependencies. That means that different packages may collide in the lock file, hence this check.