class Gem::Resolver

def resolve
  locking_dg = Molinillo::DependencyGraph.new
  Molinillo::Resolver.new(self, self).resolve(@needed.map {|d| DependencyRequest.new d, nil }, locking_dg).tsort.map(&:payload).compact
rescue Molinillo::VersionConflict => e
  conflict = e.conflicts.values.first
  raise Gem::DependencyResolutionError, Conflict.new(conflict.requirement_trees.first.first, conflict.existing, conflict.requirement)
ensure
  @output.close if defined?(@output) and !debug?
end