How to configure Kotlin multiplatform mobile library for bintray upload

[ln-12]

I am currently wokrking on an app using Kotlin multiplatform mobile. To separate some functionality, I want to split some parts of my app into dependencies. My first try is this library to monitor the connection status of the device. My build.gradle.kts is listed below.

The problem now is that after running ./gradlew bintrayUpload, not all artifacts appear in the repo. There are no iOS variants. What am I missing?

plugins {
    id("com.android.library")
    kotlin("multiplatform") version "1.4.21"
    kotlin("native.cocoapods") version "1.4.21"
    id("maven-publish")
    id("com.jfrog.bintray") version "1.8.5"
}

group = "com.github.ln12"
version = "1.0"

repositories {
    google()
    jcenter()
    mavenCentral()
}

kotlin {
    android { publishLibraryVariants("release") }

    ios()

    sourceSets {
        val commonMain by getting {
            dependencies {
                api("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.4.2-native-mt")
            }
        }
        val commonTest by getting {
            dependencies {
                implementation(kotlin("test-common"))
                implementation(kotlin("test-annotations-common"))
            }
        }
        val androidMain by getting
        val androidTest by getting {
            dependencies {
                implementation(kotlin("test-junit"))
                implementation("junit:junit:4.13.1")
            }
        }
        val iosMain by getting
        val iosTest by getting
    }

    cocoapods {
        summary = "A Kotlin multiplatform mobile library to monitor the connectivity status of the device"
        homepage = "https://github.com/ln-12/multiplatform-connectivity-status"

        // https://github.com/tonymillion/Reachability
        pod("Reachability") {
            version = "3.2"
        }
    }
}

android {
    compileSdkVersion(30)
    sourceSets["main"].manifest.srcFile("src/androidMain/AndroidManifest.xml")
    defaultConfig {
        minSdkVersion(24) // API >= 24 needed for ConnectivityManager.registerDefaultNetworkCallback()
        targetSdkVersion(30)
    }
}

// metadata is currently not supported for iOS
// https://youtrack.jetbrains.com/issue/KT-44459#focus=Comments-27-4645829.0-0
kotlin.metadata {
    compilations.matching { it.name == "iosMain" }.all {
        compileKotlinTaskProvider.configure { enabled = false }
    }
}

// taken from: https://serpro69.medium.com/publishing-a-kotlin-library-to-your-bintray-repo-using-gradle-kotlin-dsl-bdeaed54571a
val artifactName = project.name
val artifactGroup = project.group.toString()
val artifactVersion = project.version.toString()

val pomUrl = "https://github.com/ln-12/multiplatform-connectivity-status"
val pomScmUrl = "https://github.com/ln-12/multiplatform-connectivity-status"
val pomIssueUrl = "https://github.com/ln-12/multiplatform-connectivity-status/issues"
val pomDesc = "A Kotlin multiplatform mobile library to monitor the connectivity status of the device"

val githubRepoName = "ln-12/multiplatform-connectivity-status"
val githubReadme = "README.md"

val pomLicenseName = "Apache-2.0"
val pomLicenseUrl = "http://www.apache.org/licenses/LICENSE-2.0"
val pomLicenseDist = "repo"

val pomDeveloperId = "ln-12"
val pomDeveloperName = "Lorenzo Neumann"

publishing {
    publications {
        publications.withType<MavenPublication>().all {
            groupId = artifactGroup
            artifactId = artifactName
            version = artifactVersion

            pom.withXml {
                asNode().apply {
                    appendNode("description", pomDesc)
                    appendNode("name", rootProject.name)
                    appendNode("url", pomUrl)
                    appendNode("licenses").appendNode("license").apply {
                        appendNode("name", pomLicenseName)
                        appendNode("url", pomLicenseUrl)
                        appendNode("distribution", pomLicenseDist)
                    }
                    appendNode("developers").appendNode("developer").apply {
                        appendNode("id", pomDeveloperId)
                        appendNode("name", pomDeveloperName)
                    }
                    appendNode("scm").apply {
                        appendNode("url", pomScmUrl)
                    }
                }
            }
        }
    }
}

bintray {
    user = System.getenv("BINTRAY_USER")
    key = System.getenv("BINTRAY_KEY")

    publish = true

    pkg.apply {
        repo = "maven"
        name = artifactName
        userOrg = pomDeveloperId
        githubRepo = githubRepoName
        vcsUrl = pomScmUrl
        description = pomDesc
        setLabels("kotlin", "kotlin multiplatform mobile")
        setLicenses(pomLicenseName)
        desc = description
        websiteUrl = pomUrl
        issueTrackerUrl = pomIssueUrl
        githubReleaseNotesFile = githubReadme

        version.apply {
            name = artifactVersion
            desc = pomDesc
        }
    }

    project.publishing.publications.all {
        this@bintray.setPublications(*publications, name)
    }
}