How to successfully use `reanalyze`?

1

I trying to setup dce analysis for a project. I have added this to our rescript.json

    "reanalyze": {
      "analysis": ["dce", "exception"],
      "suppress": ["test", "src/libs"]
    }

Rescript’s new build system issues a warning: The field ‘reanalyze’ found in the package config of ‘kaiko-survey-tool’ is not supported by ReScript 12’s new build system.

But running the legacy build system and then reanalyze -dce still prints warnings for suppressed directories:

  ...
  Warning Dead Type
  .../test/ServerSyncPipeline_test.res:112:21-33
  state.value is a record label never used to read a value
  <-- line 112
        type state = {@dead("state.value") value: string}

Is there a way to actually suppress the warnings?