Kotlin native could not find "openssl"

[FJerabek]

I am trying to create project using this library with kotlin native on linux 64bit, but i am getting strange error about missing openssl. I have installed openssl and libssl-dev but the error still persists.

e: Could not find "openssl" in [/home/fjerabek/mqttTest, /home/fjerabek/.konan/klib, /home/fjerabek/.konan/kotlin-native-prebuilt-linux-x86_64-1.7.0/klib/common, /home/fjerabek/.konan/kotlin-native-prebuilt-linux-x86_64-1.7.0/klib/platform/linux_x64]

Execution failed for task ':compileKotlinNative'.
> Compilation finished with errors

Am i missing some other library on my system ?

[davidepianca98]

Hello, how did you include the dependency in gradle? Also it looks like you are using Kotlin 1.7.0, I have yet to try to compile with that version but I will check soon.

[FJerabek]

I am including the dependency by adding this to the build.gradle.kts file into the sourceSets block.

commonMain {
    dependencies {
        implementation("com.github.davidepianca98.KMQTT:kmqtt:0.3.2")
    }
}

The resulting build file looks like this. It is the default template that jetbrains is using for kotlin native projects only with the added dependency.

plugins {
    kotlin("multiplatform") version "1.7.0"
}

group = "org.example"
version = "1.0-SNAPSHOT"

repositories {
    mavenCentral()
    maven(url = "https://jitpack.io")
}

kotlin {
    val hostOs = System.getProperty("os.name")
    val isMingwX64 = hostOs.startsWith("Windows")
    val nativeTarget = when {
        hostOs == "Mac OS X" -> macosX64("native")
        hostOs == "Linux" -> linuxX64("native")
        isMingwX64 -> mingwX64("native")
        else -> throw GradleException("Host OS is not supported in Kotlin/Native.")
    }

    nativeTarget.apply {
        binaries {
            executable {
                entryPoint = "main"
            }
        }
    }
    sourceSets {
        commonMain {
            dependencies {
                implementation("com.github.davidepianca98.KMQTT:kmqtt:0.3.2")
            }
        }
        val nativeMain by getting
        val nativeTest by getting
    }
}

For now i am trying out the library in jvm and kotlin 1.7.0 and it working great so far, but cannot get it to work with native.

[davidepianca98]

Unfortunately Kotlin Native doesn't provide OpenSSL bindings so I usually compile my version using a script. Apparently this doesn't get included in the library files you get from Jitpack. If you want you can download the prebuilt version from here https://github.com/davidepianca98/KMQTT/blob/master/src/nativeInterop/openssl-linux-x64.klib and include it with the following code changing the directory.

val linuxArm64Main by getting {
    dependencies {
        implementation(files("src/nativeInterop/openssl-linux-x64.klib"))
    }
}

If, for whatever reason, you do not trust the prebuilt library you can build it yourself with Docker and the files in this directory: https://github.com/davidepianca98/KMQTT/tree/master/src/linuxX64Main/resources.

I will be looking for an easier way to do this, but for now this is it unfortunately.

[FJerabek]

I must be missing something :thinking:. I added the dependency to the openssl library and looks like it loaded correctly because i can use openssl library methods, but now the problem is not in compileKotlinNative task but in linkDebugExecutableNative.

e: Could not find "openssl" in [/home/fjerabek/mqttTest, /home/fjerabek/.konan/klib, /home/fjerabek/.konan/kotlin-native-prebuilt-linux-x86_64-1.7.0/klib/common, /home/fjerabek/.konan/kotlin-native-prebuilt-linux-x86_64-1.7.0/klib/platform/linux_x64]

Execution failed for task ':linkDebugExecutableNative'.
> Compilation finished with errors

When i add the klib file to one of those locations and change the name to openssl.klib gradle complains about caching

/home/fjerabek/.gradle/caches/modules-2/files-2.1/com.github.davidepianca98.KMQTT/kmqtt-linuxx64/0.3.2/704c50f7b3bf5fd394f044a485dbba73cdc81f59/kmqtt-linuxx64-0.3.2 is going to be cached, but its dependency isn't: /home/fjerabek/mqttTest/openssl

[davidepianca98]

I tried creating a brand new Kotlin Native project, then i added openssl-linux-x64.klib in the src directory and modified the build gradle file in the following way (I commented the choice of the platform because I am on Windows and I wanted to build for Linux).

plugins {
    kotlin("multiplatform") version "1.7.0"
}

group = "me.x"
version = "1.0-SNAPSHOT"

repositories {
    mavenCentral()
    maven(url = "https://jitpack.io")
}

kotlin {
    val hostOs = System.getProperty("os.name")
    val isMingwX64 = hostOs.startsWith("Windows")
    //val nativeTarget = when {
    //    hostOs == "Mac OS X" -> macosX64("native")
    //    hostOs == "Linux" -> linuxX64("native")
    //    isMingwX64 -> mingwX64("native")
    //    else -> throw GradleException("Host OS is not supported in Kotlin/Native.")
    //}
    val nativeTarget = linuxX64("native")

    nativeTarget.apply {
        binaries {
            executable {
                entryPoint = "main"
            }
        }
    }
    sourceSets {
        val commonMain by getting {
            dependencies {
                implementation("com.github.davidepianca98.KMQTT:kmqtt:0.3.2")
            }
        }
        val nativeMain by getting {
            dependencies {
                implementation(files("src/openssl-linux-x64.klib"))
            }
        }
        val nativeTest by getting
    }
}

Then I made this main file:

import mqtt.broker.Broker

fun main() {
    Broker().listen()
}

And finally I ran linkDebugExecutableNative and it's compiling correctly the binary file and it's running correctly. Please try to check for differences and let me know if changing your setup makes it work.

[FJerabek]

This is weird. The same build script works on windows (I tried it on my windows machine) but not on linux. I tried cleaning the build cache and still no difference. The gradle versions are the same. I also tried it inside wsl to try other "linux" system and i cannot get it build in wsl too.

[davidepianca98]

You are right, I have no idea what's going on, because linkReleaseExecutableNative works but linkDebugExecutableNative doesn't. I will continue to try to find the issue but it could be something wrong with the Kotlin build system.

[davidepianca98]

Solved in 0.3.3