InvalidMutabilityExceptionInvalidMutabilityException on common test with Ktor

Question

I have a multiplatform library to do few APIs calls with Ktor (2.0.0-beta-1)

class DiscoveryServicesImpl(private val client: HttpClient) : DiscoveryServices {
    override suspend fun getServers(domain: String): DAAServers {
        return client.get(Servers.Domain(domain = domain)).body()
    }
}

// Where client is created with specific engine (OkHttp for Android and Darwin for iOS)

This code works as expected (implemented in both Android and iOS apps)

To secure this code, I've added a unit test to verify that the url is well builded.

@Test
fun getServersSuccessful() {
    runBlocking {
        var _request: HttpRequestData? = null

        //Given
        val mockEngine = MockEngine {
            _request = it
        }
        val discoveryApiMock = DiscoveryApi(mockEngine)
        val service = DiscoveryServicesImpl(discoveryApiMock.client)

        //When
        val servers: DAAServers = service.getServers(domain)

        //Then
        assertEquals("https://****/$domain", _request!!.url.toString())
    }

}

But when a run this test I got an error (for iOS test only) :

> Task :api:discovery:iosTest

***.discovery.DiscoveryServicesImplTest.getServersSuccessful FAILED
    kotlin.native.concurrent.InvalidMutabilityException at /Users/teamcity1/teamcity_work/6326934d18cfe24e/kotlin/kotlin-native/runtime/src/main/kotlin/kotlin/Throwable.kt:24



kotlin.native.concurrent.InvalidMutabilityException: mutation attempt of frozen kotlin.native.internal.Ref@15cb7c8
kotlin.native.concurrent.InvalidMutabilityException: mutation attempt of frozen kotlin.native.internal.Ref@15cb7c8
    at kotlin.Throwable#<init>(/Users/teamcity1/teamcity_work/6326934d18cfe24e/kotlin/kotlin-native/runtime/src/main/kotlin/kotlin/Throwable.kt:24)
    at kotlin.Exception#<init>(/Users/teamcity1/teamcity_work/6326934d18cfe24e/kotlin/kotlin-native/runtime/src/main/kotlin/kotlin/Exceptions.kt:23)
    at kotlin.RuntimeException#<init>(/Users/teamcity1/teamcity_work/6326934d18cfe24e/kotlin/kotlin-native/runtime/src/main/kotlin/kotlin/Exceptions.kt:34)
    at kotlin.native.concurrent.InvalidMutabilityException#<init>(/Users/teamcity1/teamcity_work/6326934d18cfe24e/kotlin/kotlin-native/runtime/src/main/kotlin/kotlin/native/concurrent/Freezing.kt:24)
    at <global>.ThrowInvalidMutabilityException(/Users/teamcity1/teamcity_work/6326934d18cfe24e/kotlin/kotlin-native/runtime/src/main/kotlin/kotlin/native/concurrent/Internal.kt:109)
    at <global>.MutationCheck(Unknown Source)
    at kotlin.native.internal.Ref#<set-element>(/Users/teamcity1/teamcity_work/6326934d18cfe24e/kotlin/kotlin-native/runtime/src/main/kotlin/kotlin/native/internal/Ref.kt:12)

It's happening only on the ios target

To fix this, I've added this code pretty much everywhere (commonMain, commonTest, iosMain, iosTest) but it doesn't change anything

implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.0-native-mt") {
    version {
        strictly("1.6.0-native-mt")
    }
}

Below, my gradles files :

kotlin {
    sourceSets {
        val commonMain by getting {
            dependencies {
                implementation(Ktor.clientCore)
                implementation(Ktor.clientResources)
                implementation(Ktor.contentNegotiation)
                implementation(Ktor.clientJson)
                implementation(Ktor.clientLogging)
                implementation(Ktor.clientAuth)
                implementation(Koin.koinMultiplatform)
                implementation(project(":serialization"))
                implementation(project(":transverse:log"))

                implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.0-native-mt") {
                    version {
                        strictly("1.6.0-native-mt")
                    }
                }

            }
        }

        val commonTest by getting {
            dependencies {
                implementation(Ktor.clientMock)
                implementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.6.0-native-mt") {
                    version {
                        strictly("1.6.0-native-mt")
                    }
                }
            }
        }


        val iosMain by getting {
            dependencies {
                implementation(Ktor.clientDarwin)
            }
        }
    }
}