Using different Kotlin versions in a KMM project31 Jul 2021 Share on:
More and more Kotlin Multiplafrom projects are now using
Jetpack Compose for the Android UI and with that comes the potential inconvenience that Compose
(including recent stable version) still depends on Kotlin
1.5.10 while a number of libraries typically used in KMM projects (such as Kotlinx
Serialization and Ktor) are now using Kotlin
1.5.21. This mismatch is not typically an issue for Android applications but for say iOS client
(where shared code is built using Kotlin/Native) continuing to use 1.5.10 will causes binary incompatibility issues.
To work around this for now I’ve made following changes to a number of the KMM samples I have in GitHub,
covering at least cases where project is using using either
In both cases I’ve updated the root
build.gradle.kts to pull in new
kotlinVersion gradle property which is set by default to
This is the more straightforward update to make. We simply add
-P"kotlinVersion"="1.5.21" to gradle command in XCode run script
as shown below. Note that having done this we can actually now start to make use of new
embedAndSignAppleFrameworkForXcode task added
in Kotlin 1.5.20 (allowing the removal of the
packForXCode task in build script for shared code).
We have less direct control over gradle command line options when using
CocoaPods so for now am making use of approach recommended by
Kurt Acosta below.
What I do is I generate the podspec once, add the parameters in the script then use noPodspec() inside the cocoapods block to prevent it from being regenerated unless I have updates (which I rarely do)— Kurt Acosta (@kuuurt__) July 31, 2021
Having performed at least initial build we then add
cocoapods section in shared code build script, update the generated
podspec file as shown below (adding
-PkotlinVersion="1.5.21" \ line) and then re-run
Using different Kotlin versions in a KMM project https://t.co/NDz0QXRlkL— John O'Reilly #BlackLivesMatter (@joreilly) July 31, 2021
Wrote short blog post about how to setup a KMM project to use different Kotlin versions for the Android and iOS builds. Thanks to @kuuurt__ for recommendation on approach to use for CocoaPods setup.