This is the issue blocking me on upgrading Strikt to Kotlin 1.5 (I don’t think it will bite you using existing Strikt releases with 1.5 unless you use

Assertion.Builder<Result<*>>

) https://youtrack.jetbrains.com/issue/KT-46890

Did you try forcing boxing it before? If the compiler thinks it HAS to box it, you might always have a Result class instance like you're expecting.

Damn, the example I attached to the issue failed in a scratch file in the Strikt project, but I’m having trouble recreating it in isolation

Did you change this to 1.5? https://github.com/robfletcher/strikt/blob/a05dc166fd2240894d9ed0119700a45820fbafd3/build.gradle.kts#L46

yep

Maybe it's getting boxed for some reason where you're using it?

yeah, this is turning out to be a pain to replicate

Nice! I hope that'll get fixed soon... it seems like even trying to box it doesn't help.