warning: unknown language feature 'UnknownFeature' in passed internal argument '-XXLanguage:+UnknownFeature'
compiler/testData/cli/jvm/legacySmartCastsAfterTry.kt:8:9: error: only safe (?.) or non-null asserted (!!.) calls are allowed on a nullable receiver of type String?
    some.length
        ^
COMPILATION_ERROR