Linker errors when building for iOS

Hi, in my KMM project, I’ve added the following to shared/build.gradle.kts:

sourceSets {
        val commonMain by getting {
            dependencies {
                implementation("dev.gitlive:firebase-auth:1.0.0")
                ...

But when I try building the iOS application, I get the following linker errors:

.app/iosApp
ld: warning: Could not find or use auto-linked framework 'GoogleDataTransport'
ld: warning: Could not find or use auto-linked framework 'FirebaseCoreDiagnostics'
ld: warning: Could not find or use auto-linked framework 'FirebaseAnalytics'
ld: warning: Could not find or use auto-linked framework 'nanopb'
ld: warning: Could not find or use auto-linked framework 'FirebaseAuth'
ld: warning: Could not find or use auto-linked framework 'FIRAnalyticsConnector'
ld: warning: Could not find or use auto-linked framework 'GoogleUtilities'
ld: warning: Could not find or use auto-linked framework 'FirebaseCore'
ld: warning: Could not find or use auto-linked framework 'GoogleAppMeasurement'
ld: warning: Could not find or use auto-linked framework 'GTMSessionFetcher'
ld: warning: Could not find or use auto-linked framework 'FirebaseInstallations'
ld: warning: Could not find or use auto-linked framework 'PromisesObjC'
Undefined symbols for architecture x86_64:
  "_FIRAuthErrorDomain", referenced from:
      _cocoapods_FirebaseAuth_FIRAuthErrorDomain_getter_wrapper0 in shared(result.o)
     (maybe you meant: _cocoapods_FirebaseAuth_FIRAuthErrorDomain_getter_wrapper0, knifunptr_cocoapods_FirebaseAuth3_FIRAuthErrorDomain_getter )
  "_OBJC_CLASS_$_FIRUser", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIRMultiFactorSession", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIRPhoneAuthProvider", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIRAuthDataResult", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIRGoogleAuthProvider", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIRMultiFactorInfo", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIREmailAuthProvider", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIRGitHubAuthProvider", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIRFacebookAuthProvider", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIRActionCodeSettings", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIRTwitterAuthProvider", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIRAuth", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIROAuthProvider", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIROptions", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIRActionCodeInfo", referenced from:
      objc-class-ref in shared(result.o)
  "_OBJC_CLASS_$_FIRApp", referenced from:
      objc-class-ref in shared(result.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I noticed that, when cloning the firebase-kotlin-sdk repository and trying to build firebase-auth from there, there’s an additional Carthage step which seems to download the required frameworks and link them: *** Downloading binary-only framework FirebaseAuthBinary at "https://dl.google.com/dl/firebase/ios/carthage/FirebaseAuthBinary.json"

… but this step doesn’t seem to happen when using dev.gitlive:firebase-auth:1.0.0 as a dependency. Is there a way to solve this issue? Thanks.

[Daeda88]

sorry, forgot about that part. Add a Cartfile ${rootProject.projectDir}/ios/ containing the required Firebase dependencies: binary “https://dl.google.com/dl/firebase/ios/carthage/FirebaseAnalyticsBinary.json” == 6.30.0 binary “https://dl.google.com/dl/firebase/ios/carthage/FirebaseAuthBinary.json” == 6.30.0 binary “https://dl.google.com/dl/firebase/ios/carthage/FirebaseFirestoreBinary.json” == 6.30.0 binary “https://dl.google.com/dl/firebase/ios/carthage/FirebaseFunctionsBinary.json” == 6.30.0

[Daeda88]

I think currently the library doesnt export Firebase to projects implementing it. It just tells Xcode to import the library. To add it, in your build.gradle:

kotlin {
    ios {
        binaries {
            framework {
                isStatic = false
                transitiveExport = true

                linkerOpts("-F${rootProject.projectDir}/ios/Carthage/Build/iOS/")
                linkerOpts("-ObjC")
            }
            getTest("DEBUG").apply {
                linkerOpts("-F${rootProject.projectDir}/ios/Carthage/Build/iOS/")
                linkerOpts("-ObjC")
            }
        }
    }
   ...
   tasks {
        listOf("bootstrap", "update").forEach {
            task<Exec>("carthage${it.capitalize()}") {
                group = "carthage"
                executable = "carthage"
                args(
                    it,
                    "--project-directory", "${rootProject.projectDir}/ios/",
                    "--platform", "iOS",
                    "--cache-builds"
                )
            }
        }
    }
}

afterEvaluate {
    tasks.named("linkDebugTestIosArm64").configure {
        dependsOn(tasks.named("carthageBootstrap"))
    }
    tasks.named("linkDebugTestIosX64").configure {
        dependsOn(tasks.named("carthageBootstrap"))
    }
    tasks.named("linkDebugFrameworkIosArm64").configure {
        dependsOn(tasks.named("carthageBootstrap"))
    }
    tasks.named("linkDebugFrameworkIosX64").configure {
        dependsOn(tasks.named("carthageBootstrap"))
    }
    tasks.named("linkReleaseFrameworkIosArm64").configure {
        dependsOn(tasks.named("carthageBootstrap"))
    }
    tasks.named("linkReleaseFrameworkIosX64").configure {
        dependsOn(tasks.named("carthageBootstrap"))
    }
}