similar to <@U021SQJDJFQ> We have a KMM project wh...

# multiplatform

[Cas Van Luijtelaar]

similar to @Andrii Yanechko We have a KMM project which is compiled to a cocoapod itself. the project exists out of a bunch of sub-modules which all get exported into one “umbrella module”. One of the sub-modules uses a pod (which works just fine), but when we try to export it and build the umbrella we get a “not found” error.

sub-module:

plugins {
    `kmm-base-config`
    `kmm-artifact-publish`
    kotlin("native.cocoapods")
}

val iosDeploymentTarget: String by project

kotlin {
    sourceSets {
        val androidMain by getting {
            dependencies {
                implementation(libs.jmustache)
            }
        }
    }

    cocoapods {
        ios.deploymentTarget = iosDeploymentTarget
        pod("GRMustache", "~> 7.3.2")
    }
}

umbrella module:

...

plugins {
    `kmm-base-config`
    `kmm-artifact-publish`
    kotlin("native.cocoapods")
}

kotlin {

    cocoapods {
        summary = "Cocoapod for $libBaseName."
        homepage = libSiteUrl
        ios.deploymentTarget = iosDeploymentTarget
        authors = libDeveloperOrg
        version = libBaseVersion
        license = "Unlicensed"
        name = libBaseName
        source = "{ :git => '$libGitUrl', :tag => '$libBaseVersion' }"
        extraSpecAttributes["vendored_frameworks"] = "'$libBaseName.xcframework'"
        xcodeConfigurationToNativeBuildType["CUSTOM_RELEASE"] =
            org.jetbrains.kotlin.gradle.plugin.mpp.NativeBuildType.RELEASE

        framework {
            isStatic = false
            baseName = libBaseName
            exportedProjects.forEach { export(project(":sub-module")) }
        }

        specRepos {
            url("<https://github.com/Kotlin/kotlin-cocoapods-spec.git>")
        }
    }

    sourceSets {
        val commonMain by getting {
            dependencies {
               api(project(":sub-module"))
            }
        }
    }
}

...

when building this it results in a:

ld: framework not found GRMustache

[a-dd]

And adding pod("GRMustache", version = "~> 7.3.2", linkOnly = true) to umbrella doesn’t help, right? That’s strange

Could you share a build log with --info?

[Cas Van Luijtelaar]

this is with a linkOnly in the umbrella

Untitled

[a-dd]

Is there another framework declared in umbrella module?

[a-dd]

You’re running linkDebugFrameworkIosArm64 task and the task that builds the framework connected to cocoapods plugin would be called link**Pod**DebugFrameworkIosArm64 with this configuration. And the problem is that cocoapods plugin links dependencies only to its own framework.

[Cas Van Luijtelaar]

hmm yeah. Our build is a two step process

./gradlew clean podspec podPublishReleaseXCFramework
./gradlew kSwiftMultiplatformLibraryPodspec

it seems the kswift step is the one failing, so I’ll have to look into what it is doing

[Cas Van Luijtelaar]

Kswift is just wrapping the framework.linktask

target.binaries
            .withType<Framework>()
            .configureEach { applyToAppleFramework(it, processor, kSwiftExtension) } 

 private fun applyToAppleFramework(
        framework: Framework,
        processor: KLibProcessor,
        kSwiftExtension: KSwiftExtension
    ) {
        val linkTask: KotlinNativeLink = framework.linkTask
        linkTask.doLast(PostProcessLinkTask(framework, processor, kSwiftExtension))
        registerPodspecTask(linkTask, kSwiftExtension)
    }
...

and looking at the logs it seems this linktask is the linkDebugFrameworkIosArm64

I don’t quite understand how this relates to our setup and if/how we can change this to the linkDebugFrameworkIosArm64

[a-dd]

Can you show me ios targets definitions in umbrella?

[a-dd]

Or in the convention plugin

[a-dd]

There must be a framework declared somewhere, and with cocoapods plugin it’s a misconfiguration

[Cas Van Luijtelaar]

kotlin {
    val xcf = XCFramework()

    android {
        mavenPublication {
            artifactId = project.name
        }
    }

    listOf(
        iosX64(),
        iosArm64(),
        iosSimulatorArm64()
    ).forEach {
        it.binaries.framework {
            baseName = libBaseName
            xcf.add(this)
        }
    }

    targets.withType<org.jetbrains.kotlin.gradle.plugin.mpp.KotlinNativeTarget> {
        compilations.get("main").kotlinOptions.freeCompilerArgs += "-Xexport-kdoc"
    }
}

[a-dd]

Yep, it.binaries.framework declares the framework which can’t be built because it requires linking with the pod binary

[Cas Van Luijtelaar]

so declare the linkOnly pod in here?

[a-dd]

No (there’s no decent API for that currently). Is there a reason why you need another framework declaration?

[Cas Van Luijtelaar]

this was in a buildSrc folder that was being added to every submodule. why? 🤷🏼‍♂️

I don’t quite understand the difference between the XCFramework and framework or what to define where

[a-dd]

Let me write a short explanation of what’s happening:

Framework — basically a bundle of a binary (for single architecture and platform) and headers
XCFramework — bundle of multiple frameworks for different platforms/architectures

Frameworks in KMP are declared within targets by invoking sometarget.binaries.framework {} In Kotlin world frameworks are needed only for integration to iOS world (when you build a final artifact/binary). XCFrameworks need to be declared only when you publish them directly (not through CocoaPods).

CocoaPods plugin declares its own frameworks for each iOS target implicitly (it’s probably a design flaw, but it’s the way it works now). And when it builds binaries from Pod-dependencies it links then only to these frameworks and ignores any other.

In practice, it means that:
1) If you’re using CocoaPods plugin, you shouldn’t declare any other frameworks. There’ll probably be an error or a warning for that soon.
2) One should declare frameworks or XCFrameworks only when it’s required.
3) And therefore declaring frameworks in a convention plugin is not a good idea, because most likely only one (maybe a few) module will need them.

[Cas Van Luijtelaar]

thanks for that, that really should be documented somewhere!

[Cas Van Luijtelaar]

removed the xcframework and instead defining it in the framework directly now:

framework {
            isStatic = false
            baseName = libBaseName
            exportedProjects.forEach { export(project(":$it")) }

            iosX64()
            iosArm64()
            iosSimulatorArm64()
        }

running into some other kswift issues now so I cannot confirm it resolved it. mainly that kSwiftMultiplatformLibraryPodspec no longer exists

[a-dd]

Now it looks like more of a kswift issue

[a-dd]

btw declaring targets inside framework block doesn’t make much sense — it works but it’s basically the same as

kotlin {
    iosX64()
    iosArm64()
    iosSimulatorArm64()

    cocoapods { framework { .... } }
}

[Cas Van Luijtelaar]

deploying has been working for us. unfortunately there are some issues with tests. mostly if one submodule depends on the submodule with the pods. and try to run the iOS tests from the submodule. it will fail with another “[pod] not found”. I guess one solution would be to add a “linkOnly” pod to all submodules that depend on it. but that’s obviously not very scalable