minimal example: a/build.gradle.kts :

import java.io.File;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

fun fileToByteBuffer(f : File) : ByteBuffer {
    val file = RandomAccessFile(f, "r")
    val fileChannel = file.getChannel()
    var i = 0
    var buffer = ByteBuffer.allocate(fileChannel.size().toInt())
    fileChannel.read(buffer)
    buffer.flip()
    return buffer
}

val filetmp = "/sda3_partition_resize_to_size"

class lexer(stm : ByteBuffer, delimiter : String) {
    val f = stm
    val delimiters = delimiter
    fun clone() {
        val ll = lexer(fileToByteBuffer(File(filetmp)), "none")
    }
}

tasks.register("test") {
    val lex = lexer(fileToByteBuffer(File(filetmp)), "none")
    println("cloning")
    lex.clone()
    println("clone sucesfull")
}

app/build.gradle :

apply from: '../a/build.gradle.kts'

preBuild.dependsOn test

Executing tasks: [assemble]


> Configure project :app
cloning

FAILURE: Build failed with an exception.

* Where:
Build file '/home/macropreprocessor/AndroidStudioProjects/kpp/app/build.gradle' line: 35

* What went wrong:
A problem occurred evaluating project ':app'.
> Could not create task ':app:test'.
   > Build_gradle$lexer.<init>(Ljava/nio/ByteBuffer;Ljava/lang/String;)V

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at <https://help.gradle.org>

BUILD FAILED in 1s