if specs_by_platform.empty?
        requiring_targets = pod_targets.select { |pt| pt.recursive_dependent_targets.any? { |dt| dt.pod_name == pod_name } }
        message = "Could not install '#{pod_name}' pod"
        message += ", depended upon by #{requiring_targets.to_sentence}" unless requiring_targets.empty?
        message += '. There is either no platform to build for, or no target to build.'