I'm trying to use the new <Android KMP Library plugin> in my Compose MP library project and I notice...

# multiplatform

[Mofe Ejegi]

I'm trying to use the new Android KMP Library plugin in my Compose MP library project and I noticed that I can't display previews anymore - in my androidMain or commonMain.

I suspect it has something to do with the single variant approach the Android KMP library plugin uses.
I reverted to the plain androidLibrary plugin and they're back.

The Render error is:
The following classes could not be instantiated:
- androidx.compose.ui.tooling.ComposeViewAdapter

Has anyone else experienced this?

[Mofe Ejegi]

The suspicion comes from an observation I made when I switch my build variant in a typical android project to any release variant. I get a similar render error when this happens. (Since I normally use debugImplementation)

[Taush Sampley]

IIRC the new plugin gets rid of build types; there is no debug/release with the new plugin. If you’re still trying to add the preview dependency using debugImplementation, then it’s trying to add the dependency to a classpath that doesn’t exist. I’d expect some kind of error but maybe it just prints a warning? 🤷🏻 lemme see if I can find the doc about the build variant change.

[Taush Sampley]

oh, yea, it’s in the doc you linked: https://developer.android.com/kotlin/multiplatform/plugin#features first bullet point “Single Variant Architecture”

[Mofe Ejegi]

Yup. That was the first thing I noticed.

But the new plugin doesn't even support any debugImplementation or releaseImplementation functions. It shows an error if you attempt to write those.

And I'm using a plain implementation to apply the uiTooling artifact to the androidMain target. It seems like in the process of migrating to a Single variant, preview tooling support got left behind.

[Mofe Ejegi]

Of course, I could be wrong. I'm still trying out various combinations just to make sure. Even if the Compose MP ui tooling isn't working, the standard androidx.compose.ui:ui-tooling for the androidMain source set should.

[Mofe Ejegi]

I should've done a proper search before asking this.
Looks like it's already asked here: https://kotlinlang.slack.com/archives/C3PQML5NU/p1748975773510059

[Madalin Valceleanu]

Please check workaround described here: https://issuetracker.google.com/issues/422373442, might not work depending on your case but is something to try. At the same time, you can also disable iOS target temporary when using compose previews until issue gets fixed