How to save a file on Mac using Compose Multiplatform for Desktop

Question

I'm trying to save a text file with the app logs in my compose multiplatform project on a Mac, but it only works with debug builds. The distributable version throws an exception at runtime.

If I create the distributable via gradle packageDmg and I open the generated app I get the following exception:

java.nio.file.FileSystemException: /logs: Read-only file system

The app tries to create a folder relative to it's path, named logs where it should put a txt file.

If I run it locally via IntelliJ IDEA it creates the file in the specified folder as expected.

This is the code I'm running:

import java.io.FileOutputStream
import java.text.SimpleDateFormat
import java.util.*

object FileUtils {
    fun getOrCreateFile(dirName: String, fileName: String): File {
        Paths.get(dirName).createDirectories()
        val file = Paths.get(dirName, fileName)

        if (!Files.exists(file)) {
            file.createFile()
        }

        return file.toFile()
    }
}

fun saveLogsToFile(text: String) {
    val today = SimpleDateFormat("dd-M-yyyy").format(Date())
    val file = FileUtils.getOrCreateFile(
        "logs",
        "$today.txt"
    )

    FileOutputStream(file, true).bufferedWriter().use { fileWriter ->
        fileWriter.write(text + "\n")
    }
}