ScopedEmitter.re

      let%lwt (emitted_modules, size) =
        Lwt_io.with_file(
          ~mode=Lwt_io.Output,
          ~perm=0o777,
          ~flags=Unix.[O_CREAT, O_TRUNC, O_WRONLY, O_SHARE_DELETE, O_SYNC, O_NONBLOCK],
          temp_file,
          run(start_time, ctx),
        );

      Logs.debug(x => x("Before RENAME --- %s", temp_file));
      Logs.debug(x => x("Before RENAME output: %s", ctx.output_file));
      let%lwt () = Lwt_unix.rename(temp_file, ctx.output_file);