RLS freezes on "building" or "build_script_build"

[rasky]

RLS is stuck in the "building" or "build_script_build" phase. There is not generated output, save for this error any time I save a file:

  Message: Reformat failed to complete successfully
  Code: -32603

I tried activate the log file and it's always zero bytes (nothing is written there).

How can I debug this issue?

[woss]

check https://github.com/rust-lang/rls/issues/1620