A script has an annotation on a variable, for example:
An AST Transformation adds a method that initializes the input reference and the declaration is transformed to:
def input = someMethod("some.input.reference")
The someMethod() method contains a staticMethodCall.
If several scripts that are instrumented this way are called after each other then in the second script always a GroovyBug exception occurs, see attachment.
If the script is called stand-alone then everything is fine.
The order in which the scripts is called doesn't matter.
I included a more detailed code example in the attachment.
It seems there is some kind of bug with static method calls in AST transformations.