We are using the JBoss EAP XP 4.0.0 and the included microprofile rest client (org.jboss.resteasy.resteasy-client-microprofile@3.15.3.Final-redhat-00001) to send requests in a setting where proxies are used which leads to the following exception since the system property "http.nonProxyHosts" contains a hostname with the '*'.
Caused by: java.util.regex.PatternSyntaxException: Dangling meta character '*' near index 0
The package org.jboss.resteasy.resteasy-client-microprofile contains the following already known bug: https://github.com/resteasy/resteasy-microprofile/issues/10
The bug is fixed in org.jboss.resteasy.microprofile:microprofile-rest-client but not in the package used by the expansion pack.

How to reproduce:

JBoss EAP Version: 7.4.10
JBoss EAP XP: 4.0.0

Add a WAR file that does the following:

Set system properties "http.proxyHost" and "http.nonProxyHosts" where the host name in "http.nonProxyHosts" contains an '*'.
System.setProperty("http.nonProxyHosts", "*.remaining-part-of-host-name");System.setProperty("http.proxyHost", "some-other-host");

Call the following lines to create a RestClient
RestClientBuilder.newBuilder()
.baseUrl(url)
.build(SomeRestClient.class);
where SomeRestClient has the RegisterRestClient annotation.
@org.eclipse.microprofile.rest.client.inject.RegisterRestClient()
public interface SomeRestClient {...}