Instructions on new bootstrap?

[Paul Smith]

Are there instructions on how the new model of bootstrap is supposed to
be used somewhere?  I can't quite figure it out.

I pulled in the latest gnulib/build-aux/bootstrap and ran it, then when
it was complete git shows:

Changes not staged for commit:
        modified:   bootstrap

Untracked files:
        autogen.sh
        autopull.sh
        bootstrap-funclib.sh

Looking at bootstrap now it was replaced with gnulib/top/bootstrap and
these extra files were added.  It would be nice if, at least, I could
have these files put somewhere besides my root directory.

So I went and looked at the build-aux/bootstrap and it says:

  # Set this to true in bootstrap.conf to enable --bootstrap-sync by
  # default.
  bootstrap_sync=false
    ...
    --bootstrap-sync)
      bootstrap_sync=true;;
    ...

which seems to imply that unless I add that flag or set bootstrap_sync
in my bootstrap.conf file (which I did not), the sync won't happen. 
But then later I see this:

  if ! test -f "$medir"/bootstrap-funclib.sh; then
    # We have only completed the first phase of an upgrade from a bootstrap
    # version < 2022-07-24. Need to do the second phase now.
    bootstrap_sync=true
  fi

so it seems like all the settings of bootstrap-sync are not useful
since this will overwrite them with prejudice if that file doesn't
exist.

Is this a bug in the script, or am I confused about how all this is
supposed to work in the modern era?