Mill 0.12.0-RC1 is out

[lihaoyi]

The upcoming 0.12.0 release focuses on improving the scalability of Mill builds: in terms of performance, code organization, adherence to best practices, and community. RC1 is intended to give people a time to try out the major changes so that any issues can be resolved before the release of 0.12.0 final (targeting end-September 2024).

See the changelog for more details https://github.com/com-lihaoyi/mill#0120-rc1---2024-09-09

[dangdennis]

Thanks for 0.12! Works fine for my small application so far. However I want to share a small, but resolved, issue.

After a mill clean, using build.mill and 0.12.0-RC1, I discovered that 0.12.0-RC1 generated a new out/all/compile.super/all.json unlike the usual out/all/compile.json.

In my build.sc, my task mill app.compile is a single task to compile all my repo's packages.

object all extends CommonModule {
    def compile = T.command {
        api.compile()
        test.compile()
        cli.compile()
    }
}

With 0.12.0-RC1 and build.sc renamed to build.mill, I get error

An unexpected error occurred
Exception in thread "MillServerActionRunner" java.nio.file.NoSuchFileException: /Users/dennis/Desktop/projectx/api/out/all/compile.json

As shown by the error, out/all/compile.json was missing. But we have a new out/all/compile.super/all.json. Rewriting the task to below solved my issue, and the out/all/compile.super/ directory is no longer created.

object all extends Module {
  def moduleDeps = Seq(api, test, cli)

  def compile = T {
    T.traverse(moduleDeps)(_.compile)
  }
}