How to avoid knownDirectSubclasses errors in Scala 2.12.4+?

This is the error I get (stripped down project here):

[IJ]> ~web-server/re-start
[info] Compiling 4 Scala sources to /home/brandon/workspace/ProjectGists/CCRS_knownDirectSubclasses/web-server/target/scala-2.12/classes...
[error] knownDirectSubclasses of FileCommand observed before subclass ExecFile registered
[error] one error found
[error] (web-server/compile:compileIncremental) Compilation failed
[error] Total time: 1 s, completed Apr 26, 2018 3:00:49 PM

Workaround suggestions would also be much appreciated. Two non-workaround ways of getting the error to go away:

  1. Delete ExecFile
  2. Delete AutowireServer’s dispatch method

I also posted this at due to being possibly related, but it may be a different issue. However, I think it is definitely related, as other posts seem to describe issues with autogenerated classes being the issue, and something related to boopickle is problem happening here.

I have a project that contains a file in the top level package called aaaCompileFirst.scala. It contains all the Enumeratum enums. It’s the only workaround I’ve found to avoid this. It is definitely not fixed in 2.12.4.

Hmm, that’s good to know. I guess I can’t use that as a workaround though, or not directly, since presumably part of the problem is some classes are being generated from macros that I’m using, which end up causing the problem

I can’t pretend to follow the partial fix Miles implemented but Enumeratum is full of macros and if the compiler doesn’t encounter these right at the beginning I get the issue. It’s probably worth a try.