In my project, adding a dependency on org.wildfly.swarm:arquillian brings in weird versions of various Arquillian JARs. The root Swarm POM specifies 1.1.12.Final, but most of Arquillian JARs brought in are actually 1.1.10.Final. Some of them, strangely, are indeed 1.1.12.Final. This causes unpredictability, confusion and potentially also bugs that would be hard to figure out. Also if we were to upgrade Arquillian in Swarm (there's 1.1.13.Final out there), it's likely we wouldn't upgrade much.
Here's a minimal reproducer: https://github.com/Ladicek/swarm-arquillian-versions Just clone it and run mvn clean test. For each core Arquillian JAR, it prints an Implementation-Version from its MANIFEST.MF. (This is only possible to do inside the @Deployment method, or maybe in a @RunAsClient test, because inside the in-container test method, the Arquillian JARs are actually artificially constructed by Arquillian's ArchiveAppender-s.)
Running mvn dependency:tree shows the same version numbers, so my guess is that Maven is the culprit.