How should I set opt-in in a multiplatform project?

sourceSets {
    all { languageSettings.optIn("opt.in.Class") }
    commonMain {
        dependecies {
            implementation("dep.that.require.annotation")
        }
    }

}

If I do it that way I get a warning that

opt.in.Class

is unresolved for some source sets.

sourceSets {
    commonMain {
        languageSettings.optIn("opt.in.Class")
        dependecies {
            implementation("dep.that.require.annotation")
        }
    }

}

If I do it this way I get an error that opt in should be applied to all dependent source sets.

The first way works for me. Which source set does it say it's unresolved for?

androidMain

. I get the following warning when build project:

> Task :module:compileDebugKotlinAndroid
w: Opt-in requirement marker com.russhwolf.settings.ExperimentalSettingsApi is unresolved. Please make sure it's present in the module dependencies

Seems odd. Have you tried also adding it explicitly to the

androidMain

source set?

Adding opt-in or dependency on lib?

Opt-in

That worked. I can’t understand why though. As it seems to me

all { }

should’ve added opt-in to all source sets

I would think so. Maybe file a bug.

Okay. Thank you for your help!