Re: testsuite -C dir

[Ralf Wildenhues]

Libtool mainline uses Autotest and a section

  m4_divert_push([PREPARE_TESTS])
  ...
  m4_divert_pop([PREPARE_TESTS])

to set some values, e.g.,
  eval `$LIBTOOL --config | grep '^EGREP='`

This fails with Autoconf mainline now (after the recent patches) because
$LIBTOOL is not set yet; it is set in the call from the Makefile with
  ./testsuite LIBTOOL=...

This causes breakage of several tests in the suite.

I understand that Libtool uses a diversion that has not been documented
in the manual; but IIRC then Autotest's diversion were intended to be
usable by the user, and anyway I dislike breaking interfaces
gratuitously.  Could you please fix this in Autotest?  Otherwise, at
least there should be a prominent note that users cannot rely on this.
But that would be very sad, as PREPARE_TESTS is the only place inside
the testsuite that developers can introduce initializations that hold
for all tests and not have to resort to files generated only at
config.status time, and it's currently documented in the code to come
after argument parsing.

Thank you,
Ralf