WarExploder assumes that the build system uses a target directory for build artifacts. This causes problems when using Gradle and the gradle-jpi-plugin since Gradle uses a build directory for build artifacts. See WarExploder.java#L91.

When using core versions >1.544 and <1.592, builds will fail when the target directory does exist. This has been introduced in bc4c1326 and fixed in 9aaeb0a3.