private static String resolveXDHome() {
			Assert.state(
					CommandLinePropertySourceOverridingListener.getCurrentEnvironment() != null,
					"Expected to be called in the control flow of "
							+ CommandLinePropertySourceOverridingListener.class.getSimpleName()
							+ ".onApplicationEvent()");
			//TODO: I'm not sure if this works. compare to resolveMessageBusPath() above
			String resolved = CommandLinePropertySourceOverridingListener.getCurrentEnvironment()
					.resolvePlaceholders("${xd.home:.}/lib/*");
			resolved = StringUtils.cleanPath(resolved).replace("//", "/");
			return "file:" + resolved;
		}
Attempt to resolve the xd.home placeholder and take care of corner cases where the user may have provided a
trailing slash, etc.
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/server/options/ResourcePatternScanningOptionHandlers.java