spock: IllegalStateException: Invisible parameter type of kotlin.jvm.internal.DefaultConstructorMarker

I have a Kotlin class:

open class SomeClass(val cheese: String = "brie") {
    fun foo() = "bar"
}

… and a Spock test:

class OpenTest extends Specification {

    def "should be able to mock"() {
      given:
        def someMock = Mock(SomeClass)
        someMock.foo() >> "cheese"

      expect: "that we actually can mock it"
        someMock.cheese == "brie"
        someMock.foo() == "cheese
    }
}

… using the following Gradle dependencies:

testCompile(
    "org.spockframework:spock-core:1.1-groovy-2.4",
    "net.bytebuddy:byte-buddy:1.7.5",
)

Running the test gives me:

java.lang.IllegalArgumentException: Could not create type

	at net.bytebuddy.TypeCache.findOrInsert(TypeCache.java:140)
	at net.bytebuddy.TypeCache$WithInlineExpunction.findOrInsert(TypeCache.java:346)
	at net.bytebuddy.TypeCache.findOrInsert(TypeCache.java:161)
	at net.bytebuddy.TypeCache$WithInlineExpunction.findOrInsert(TypeCache.java:355)
	at org.spockframework.mock.runtime.ProxyBasedMockFactory$ByteBuddyMockFactory.createMock(ProxyBasedMockFactory.java:108)
	at org.spockframework.mock.runtime.ProxyBasedMockFactory.create(ProxyBasedMockFactory.java:65)
	at org.spockframework.mock.runtime.JavaMockFactory.createInternal(JavaMockFactory.java:59)
	at org.spockframework.mock.runtime.JavaMockFactory.create(JavaMockFactory.java:40)
	at org.spockframework.mock.runtime.CompositeMockFactory.create(CompositeMockFactory.java:44)
	at org.spockframework.lang.SpecInternals.createMock(SpecInternals.java:51)
	at org.spockframework.lang.SpecInternals.createMockImpl(SpecInternals.java:296)
	at org.spockframework.lang.SpecInternals.createMockImpl(SpecInternals.java:286)
	at org.spockframework.lang.SpecInternals.MockImpl(SpecInternals.java:105)
	at no.finn.travel.shared.common.kotlin.OpenTest.should be able to mock #subject(OpenTest.groovy:11)
Caused by: java.lang.IllegalStateException: Invisible parameter type of kotlin.jvm.internal.DefaultConstructorMarker arg2 for public no.finn.travel.shared.common.kotlin.SomeClass$SpockMock$bAkOnnH5(java.lang.String,int,kotlin.jvm.internal.DefaultConstructorMarker)
	at net.bytebuddy.dynamic.scaffold.InstrumentedType$Default.validated(InstrumentedType.java:925)
	at net.bytebuddy.dynamic.scaffold.MethodRegistry$Default.prepare(MethodRegistry.java:465)
	at net.bytebuddy.dynamic.scaffold.subclass.SubclassDynamicTypeBuilder.make(SubclassDynamicTypeBuilder.java:162)
	at net.bytebuddy.dynamic.scaffold.subclass.SubclassDynamicTypeBuilder.make(SubclassDynamicTypeBuilder.java:155)
	at net.bytebuddy.dynamic.DynamicType$Builder$AbstractBase.make(DynamicType.java:2639)
	at net.bytebuddy.dynamic.DynamicType$Builder$AbstractBase$Delegator.make(DynamicType.java:2741)
	at org.spockframework.mock.runtime.ProxyBasedMockFactory$ByteBuddyMockFactory$1.call(ProxyBasedMockFactory.java:113)
	at org.spockframework.mock.runtime.ProxyBasedMockFactory$ByteBuddyMockFactory$1.call(ProxyBasedMockFactory.java:110)
	at net.bytebuddy.TypeCache.findOrInsert(TypeCache.java:138)
	... 13 more

The test works without the byte-buddy dependency.

(ref. https://github.com/raphw/byte-buddy/issues/350 )