Re: [PATCH cygport v3] autotools.cygclass: correctly detect Autoconf 2.70+

[Jon Turney <jon.turney@dronecode.org.uk>]

On 14/03/2022 22:15, Adam Dinwoodie wrote:
> The latest version of Autoconf is 2.71, but the version detection
> incorrectly considers 2.70 and higher as being the same as 2.59 and
> lower for the purposes of specifying documentation directories.  Correct
> that, and make the version detection a bit more future-proof by parsing
> out the actual version parts and performing numeric comparison.
> 
> While we're at it, add a bit more commentary explaining the intent of
> the different behaviour over the different Autoconf versions.

I applied this.

But it seems no good deed goes unpunished...

>   	configure="${confdir}/configure"
> -	confver=$(grep -m 1 'GNU Autoconf' ${configure} | cut -d ' ' -f 6)
> +	confver="$("$configure" --version | sed -rn 's/.*GNU Autoconf ([0-9\.]+)/\1/p')"
> +	confver_maj=${confver%%.*}
> +	confver_min=${confver##*.}
> +	if [ $confver_maj -ne 2 ]
> +	then
> +		error "unexpected autoconf version";
> +	fi

When rebuilding 'dialog' to update the SRC_URI, I get:

> /usr/share/cygport/cygclass/autotools.cygclass: line 658: [: -ne: unary operator expected
> /usr/share/cygport/cygclass/autotools.cygclass: line 689: [: -ge: unary operator expected
> /usr/share/cygport/cygclass/autotools.cygclass: line 703: [: -ge: unary operator expected

It seems that the configure script for that it customized somehow and 
doesn't output anything matching that regex:

> $ ./configure --version
> 
> Copyright 2003-2020,2021        Thomas E. Dickey
> Copyright 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001
> Free Software Foundation, Inc.
> This configure script is free software; the Free Software Foundation
> gives unlimited permission to copy, distribute and modify it.

I think that if $confver is empty, that should be an error, and then 
perhaps there needs to be a variable which can be set to override 
autodection of the ./configure script version (e.g. something like 
'CONF_VERSION=2.60')