Hi. For everyone using KMM with Ktor and Coroutin...

# multiplatform

[Alen Kirm]

Hi.

For everyone using KMM with Ktor and Coroutines dependency, which versions of these two are you using? 🙏
So far, I was only able make it work with Ktor 1.6.7 and Coroutines 1.5.1-new-mm-dev2 but ./gradlew <module>:compileKotlinMetadata gradle tasks are failing.

[Mitchell Syer]

Coroutines 1.6.0 comes with support for the new mm, so no need for 1.5.1-new-mm-dev2

[hfhbd]

Ktor 1.6.7 and coroutines 1.6.0-native-mt with

kotlin.native.binary.memoryModel=experimental
kotlin.native.binary.freezing=disabled

[Paul Weber]

@Mitchell Syer I was having very weird problems with Ktor and the standard 1.6.0 coroutines.

I’m using 1.5.2-native-mt still. Otherwise same as @hfhbd

[Mitchell Syer]

This should help, it suggests using a build of Ktor made for the new MM https://github.com/JetBrains/kotlin/blob/master/kotlin-native/NEW_MM.md

[Alen Kirm]

@Mitchell Syer Thanks, but using Ktor 1.6.2-native-mm-eap-196 and Coroutines 1.6.0 results in: Could not find io.ktor:ktor-client-android:1.6.2-native-mm-eap-196.

[Mitchell Syer]

Its in a seperate maven repo, it should be listed in the guide

[Alen Kirm]

I think, it should work with latest Ktor 1.6.7 and Coroutines 1.6.0.
But having this two set up, ./gradlew umbrellaModule:assembleXCFramework fails with:

e: Module "io.ktor:ktor-network" has a reference to symbol kotlinx.coroutines/SingleThreadDispatcher|null[0]. Neither the module itself nor its dependencies contain such declaration.

This could happen if the required dependency is missing in the project. Or if there is a dependency of "io.ktor:ktor-network" that has a different version in the project than the version that "io.ktor:ktor-network" was initially compiled with. Please check that the project configuration is correct and has consistent versions of all required dependencies.

Any idea? 😕

[Mitchell Syer]

Hmm, then your best bet may be to use the Ktor 2.0.0 beta, which looks to have support for the new MM

[hfhbd]

coroutines 1.6.0 is not yet supported with ktor, only 1.6.0-native-mt.
a) use ktor 1.6.2-native-mm-eap-196 and coroutines 1.5.1-new-mm-dev2
b) wait for the next beta of ktor 2.0.0-beta2 and use coroutines 1.6.0
c) use ktor 1.6.7 and coroutines 1.6.0-native-mt

[Alen Kirm]

Thank you both for your help! 🙏

However, neither of this solutions seem to work for my case, so I’ll have to dig a bit deeper to find out what is going on with ktor stuff.

Still getting Module "io.ktor:ktor-network" has a reference to symbol kotlinx.coroutines/SingleThreadDispatcher|null[0] error using (C) versions above 🤷‍♂️

[hfhbd]

Thats strange. Do you have a sample/reproducer? For my simple playground demo, this combination works: https://github.com/hfhbd/ComposeTodo

[Alen Kirm]

Hm. Could be somehow related to ktor-cio.
So we are using:

"ktor-cio" to "io.ktor:ktor-client-cio:$ktorVersion",
"ktor-core" to "io.ktor:ktor-client-core:$ktorVersion",

and coroutines. Tried 1.6.0-native-mt but no luck. Only 1.5.1-new-mm-dev2 seem to be working with Ktor 1.6.7 but in this case, compileKotlinMetadata gradle task fails 😕 In case of 1.6.7 and 1.6.0-native-mt, there is Module "io.ktor:ktor-network" has a reference to symbol kotlinx.coroutines/SingleThreadDispatcher|null[0] error and linkDebugFrameworkIosArm64 gradle task fails 🤷‍♂️ 😞

[hfhbd]

do you try to use cio on iOS?

[Alen Kirm]

ktor-cio is then used as implementation inside commonMain dependencies yes, and this module is then exported inside iOS umbrella framework

[Alen Kirm]

In case of Ktor 1.6.7 and Coroutines 1.5.1-new-mm-dev2, gradle task moduleB:compileKotlinMetadata fails with error:

Execution failed for task ':moduleB:compileKotlinMetadata'.
> Error while evaluating property 'filteredArgumentsMap' of task ':moduleB:compileKotlinMetadata'
   > Could not resolve all files for configuration ':moduleB:metadataCompileClasspath'.
      > Could not find org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.1-new-mm-dev2.
        Required by:
            project :moduleB > project :moduleA

So we have Umbrella module, which exports moduleA and moduleB. Also moduleB has dependency on moduleA.

[Sam]

I recall cio not being supported on iOS targets (this may have changed at some point). Normal ktor client on iOS delegates to using NSURLSession which is better for mobile apps. The last I looked it didn't support web sockets which may be a problem for you. Otherwise, it is great.

[Alen Kirm]

@Sam Thanks for the info, will keep it in mind.
Will update you guys once we find a solution, thanks!

[Alen Kirm]

Hi all! Just an update in case anybody faces this issue 😄

We’ve managed to get it work using Ktor 2.0.0-eap-317 and Coroutines 1.6.0-native-mt.
Reference: https://youtrack.jetbrains.com/issue/KT-51145

Thank you all!