DeploymentHandlerUtil.deploy does a check for duplicate runtime names, and if found calls ServerLogger.ROOT_LOGGER.runtimeNameMustBeUnique(String existingDeployment, String runtimeName). But when it does so it passes as 'existingDeployment' the name of the 'new' deployment, not the existing one. This results in a confusing error message, e.g. when deploying foo-1.0.2.war when there is already a foo-1.0.1.war:

'There is already a deployment called foo-1.0.2.war with the same runtime name foo.war'.