Autoconf's `GUILE_CHECK' macro broken

[Ludovic Courtès]

Hi,

It looks like the Autoconf `GUILE_CHECK' macro (or perhaps Guile itself)
is broken.  In both Guile 1.6 and 1.7, it is defined as follows:

  # GUILE_CHECK -- evaluate Guile Scheme code and capture the return value
  #
  # Usage: GUILE_CHECK_RETVAL(var,check)
  #
  # @var{var} is a shell variable name to be set to the return value.
  # @var{check} is a Guile Scheme expression, evaluated with "$GUILE -c", and
  #    returning either 0 or non-#f to indicate the check passed.
  #    Non-0 number or #f indicates failure.
  #    Avoid using the character "#" since that confuses autoconf.
  #
  AC_DEFUN([GUILE_CHECK],
   [AC_REQUIRE([GUILE_PROGS])
    $GUILE -c "$2" > /dev/null 2>&1
    $1=$?
   ])

However, both versions of Guile return zero, regardless of whether the
expression passed to `-c' returned false or not.

Actually, my guess would be that Guile is broken, not the macro.  But
then, I'd be surprised to be the first one hitting that problem.

Thanks,
Ludovic.