构建 iOS 框架时找不到 Ktor 和 kotlinx 依赖项

Question

我正在尝试为我的Kotlin/Native项目添加ktor和kotlinx支持（确切地说是serialization和coroutines）。所有库在Android版本的项目上都能正常工作，但是当我尝试编译Xcode项目时，出现了错误提示找不到kotlinx.serialization和kotlinx.coroutines库：

src/commonMain/kotlin/.../.kt:4:16: error: unresolved reference: coroutines
import kotlinx.coroutines.CoroutineDispatcher
               ^
src/commonMain/kotlin/.../.kt:5:16: error: unresolved reference: serialization
import kotlinx.serialization.json.JSON

这是我的项目 gradle 文件：

以下是需要翻译的内容：

plugins {
    id 'kotlin-multiplatform' version '1.3.11'
    id 'kotlinx-serialization' version '1.3.0'
}

ext {
    ktor_version = '1.0.1'
    kotlinx_version = '1.1.0'
}

repositories {
    maven { url "https://kotlin.bintray.com/ktor" }
    maven { url "https://kotlin.bintray.com/kotlinx" }
    google()
    jcenter()
    mavenCentral()
}

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android-extensions'

configurations {
    compilerPlugin
}

android {
    compileSdkVersion 27
    defaultConfig {
        applicationId "org.jetbrains.kotlin.mpp_app_android"
        minSdkVersion 15
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:27.1.1'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'

}

kotlin {
    targets {
        fromPreset(presets.android, 'android')
        // This preset is for iPhone emulator
        // Switch here to presets.iosArm64 (or iosArm32) to build library for iPhone device
        fromPreset(presets.iosX64, 'ios') {
            compilations.main.outputKinds('FRAMEWORK')
        }
    }
    sourceSets {
        commonMain {
            dependencies {
                implementation 'commons-codec:commons-codec:1.10'
                implementation 'org.jetbrains.kotlin:kotlin-stdlib-common'
                implementation("io.ktor:ktor-client:$ktor_version")
                implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core-common:$kotlinx_version"
                implementation "org.jetbrains.kotlinx:kotlinx-serialization-runtime-common:0.9.1"
            }
        }
        commonTest {
            dependencies {
                implementation 'org.jetbrains.kotlin:kotlin-test-common'
                implementation 'org.jetbrains.kotlin:kotlin-test-annotations-common'
            }
        }
        androidMain {
            dependencies {
                implementation 'org.jetbrains.kotlin:kotlin-stdlib'
                implementation("io.ktor:ktor-client-android:$ktor_version")
                implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$kotlinx_version"
                implementation "org.jetbrains.kotlinx:kotlinx-serialization-runtime:0.9.1"
            }
        }
        androidTest {
            dependencies {
                implementation 'org.jetbrains.kotlin:kotlin-test'
                implementation 'org.jetbrains.kotlin:kotlin-test-junit'
            }
        }
        iosMain {
            dependencies {
                implementation("io.ktor:ktor-client-ios:$ktor_version")
                implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core-native:$kotlinx_version"
                implementation "org.jetbrains.kotlinx:kotlinx-serialization-runtime-native:0.9.1"
            }
        }
        iosTest {
        }
    }
}

// This task attaches native framework built from ios module to Xcode project
// (see iosApp directory). Don't run this task directly,
// Xcode runs this task itself during its build process.
// Before opening the project from iosApp directory in Xcode,
// make sure all Gradle infrastructure exists (gradle.wrapper, gradlew).
task copyFramework {
    def buildType = project.findProperty("kotlin.build.type") ?: "DEBUG"
    def target = project.findProperty("kotlin.target") ?: "ios"
    dependsOn "link${buildType.toLowerCase().capitalize()}Framework${target.capitalize()}"

    doLast {
        def srcFile = kotlin.targets."$target".compilations.main.getBinary("FRAMEWORK", buildType)
        def targetDir = getProperty("configuration.build.dir")
        copy {
            from srcFile.parent
            into targetDir
            include 'app.framework/**'
            include 'app.framework.dSYM'
        }
    }
}

任何帮助都将不胜感激，谢谢！

- Spencer

Answer 1

请确保enableFeaturePreview("GRADLE_METADATA")在settings.gradle文件中。添加了这行代码后，我就可以从Xcode进行编译了。

- Spencer

Answer 2

我也遇到了这个问题。而且它突然出现在我已经工作了几个月的项目上。我确实在settings.gradle中设置了enableFeaturePreview('GRADLE_METADATA')。到底是怎么回事？这真的很令人沮丧；我的项目突然无法继续进行，原因不明。

- Russell Stewart