Re: GNU Autoconf test version 2.59d available

[Akim Demaille]

I would like to suggest embedding a probe in Autoconf's test suite to
check whether `!' (not as an argument to `test', but as a prefix for
any command) is portable or not.  The documentation says it is not
portable, but I haven't seen a machine that doesn't support it.  Yet
it is very handy in many situations.