2.5.3 breaks Spock delayed $spock_initializeFields for final fields

[Leonard Brünings]

Hi,

it seems that 2.5.3 introduced some additional checks that causes these
exceptions:

|java.lang.IllegalAccessError: Update to static final field
spock.util.concurrent.PollingConditionsSpec.$const$0 attempted from a
different method (__$swapInit) than the initializer method <clinit> at
spock.util.concurrent.PollingConditionsSpec.__$swapInit(PollingConditionsSpec.groovy)
at
spock.util.concurrent.PollingConditionsSpec.<clinit>(PollingConditionsSpec.groovy)
|

|(https://github.com/spockframework/spock/pull/900#issuecomment-420158524
is the source)|

Spock does some AST rewrites

class AClass extends Specification {
 
 String a = "test"
 final String b = "test"
}

gets transformed into

class AClass extends Specification {
    @org.spockframework.runtime.model.FieldMetadata(name = 'a', ordinal = 0, 
line = 5, initializer = true)
    private java.lang.String a 
    @org.spockframework.runtime.model.FieldMetadata(name = 'b', ordinal = 1, 
line = 6, initializer = true)
    final private java.lang.String b 

    private java.lang.Object $spock_initializeFields() {
        a = 'test'
        b = 'test'
    }
}

This allows spock to delay the initialization of fields after the
instance creation. What is the best solution for this? Should Spock
remove the final modifier, or is there a way to mark the
$spock_initializeFields method as valid initializer?

cheers
Leonard

||