Spock bug: bad assertion message

Bad output

Condition not satisfied:

"""\ $a foobar covfefe """ == """        $b foobar covfefe """
|
false

Good output

Condition not satisfied:

x==y
|| |
||         2 foobar
||         covfefe
||         
|false
|1 difference (97% similarity)
|        (1) foobar\n        covfefe\n        
|        (2) foobar\n        covfefe\n        
        1 foobar
        covfefe
        
 <Click to see difference>

MultilineStringSpec.groovy

import spock.lang.Specification
import spock.lang.Unroll

class MultilineStringSpec extends Specification {
    @Unroll def "when/then - string literal outside 'then' #label"() {
        when:
        def x="""\
        $a foobar
        covfefe
        """
        def y="""        $b foobar
        covfefe
        """

        then:
        x==y

        where:
        a | b | label
        1 | 1 | "success"
        1 | 2 | "failure"
    }

    @Unroll def "when/then - string literal inside 'then' #label"() {
        when: 'we move the string literal tot he assertion block'
        System.currentTimeMillis()

        then: 'same as above, just inlined'
        """\
        $a foobar
        covfefe
        """ == """        $b foobar
        covfefe
        """

        where:
        a | b | label
        1 | 1 | "success"
        1 | 2 | "failure"
    }

    @Unroll def "expect #label"() {
        expect:
        """\
        $a foobar
        covfefe
        """=="""        $b foobar
        covfefe
        """

        where:
        a | b | label
        1 | 1 | "success"
        1 | 2 | "failure"
    }
}