Simply changing the Groovy version in a Springboot Gradle project won't cut it. Trying to force the version with
will result in errors building the project:
FAILURE: Build failed with an exception. * What went wrong: Execution failed for task ':compileGroovy'. > org/codehaus/groovy/ast/MethodCallTransformation
The problem there is, that Springboot manipulates the dependencies via the plugin after the fact. So we end up with mixed 2.4 (which is the default for Springboot 2 right now) and the desired 2.5.
To solve this, we need to change the Groovy version as described in Customizing managed versions .
Instead of changing the version at the dependency, add the following at the top level of the build.gradle:
ext['groovy.version'] = '2.5.0'