Not found : Type Build (Unresolved 'Build') - scala

Question

I'm getting the following set of errors, which I belive is caused by the sbt-assembly plugin that I is used.
In fact the object declaration of ;
object Build extends **Build** { (here Build is unresolved).
The error is as follows,
Error:Error while importing SBT project:<br/><pre>
[info] Loading settings from assembly.sbt,plugins.sbt ...
[info] Loading project definition from C:\Users\ShakthiW\IdeaProjects\TestProject\project
[error] <path>\Build.scala:4:22: not found: type Build
[error] object Build extends Build{
[error] ^
[error] <path>\Build.scala:8:80: value map is not a member of (sbt.TaskKey[sbt.librarymanagement.UpdateReport], sbt.SettingKey[java.io.File], sbt.SettingKey[String])
[error] def copyDepTask = copyDependencies <<= (update, crossTarget, scalaVersion) map {
[error] ^
[error] <path>\Build.scala:19:16: too many arguments (3) for method apply: (id: String, base: java.io.File)sbt.Project in object Project
[error] Note that 'settings' is not a parameter name of the invoked method.
[error] settings = Defaults.defaultSettings ++ Seq(
[error] ^
[error] three errors found
[error] (compile:compileIncremental) Compilation failed
A quick resolve is highly appreciated.
My Build.scala looks like this.
import sbt.Keys._
import sbt._
object MyBuild extends Build {
lazy val copyDependencies = TaskKey[Unit]("copy-dependencies")
def copyDepTask = copyDependencies <<= (update, crossTarget, scalaVersion) map {
(updateReport, out, scalaVer) =>
updateReport.allFiles foreach { srcPath =>
val destPath = out / "lib" / srcPath.getName
IO.copyFile(srcPath, destPath, preserveLastModified=true)
}
}
lazy val root = Project(
"root",
file("."),
settings = Defaults.defaultSettings ++ Seq(
copyDepTask
)
)
}
Also, I do rekon there is a issue with sbt-assembly upgrades as well which I'm not entirely aware of.

Answer 1

In sbt version 1.0.x, some key dependencies operators were removed. See the migration docs: https://www.scala-sbt.org/0.13/docs/Migrating-from-sbt-012x.html
Here is an short tutorial for writing Build.scala for sbt version 1.0.x: https://alvinalexander.com/scala/sbt-how-to-use-build.scala-instead-of-build.sbt.
You can also refer to build.scala of an existing project for more ref, eg. scalaz.