 
 		for (node, dependencies) in edges {
 			str += "\n\t\(node.project) ->"
-			for (dep, _) in dependencies {
+			for dep in dependencies {
 				str += "\n\t\t\(dep)"
 			}
 		}

	}
}

/// A poor person's Set.
private typealias DependencyNodeSet = [DependencyNode: ()]

/// Represents an acyclic dependency graph in which each project appears at most
/// once.
///

private func mergeGraphs(lhs: DependencyGraph, rhs: DependencyGraph) -> Result<DependencyGraph, CarthageError> {
	var result: Result<DependencyGraph, CarthageError> = .success(lhs)

	for root in rhs.roots {
		result = result.flatMap { (var graph) in
			return graph.addNode(root, dependencyOf: nil).map { _ in graph }
		}
	}

	for (node, dependencies) in rhs.edges {
		for dependency in dependencies {
			result = result.flatMap { (var graph) in
				return graph.addNode(dependency, dependencyOf: node).map { _ in graph }
			}
