Re: [PATCH 0/2] First steps in making autoconf ensure a POSIX shell

[Eric Blake]

On 11/07/2012 09:56 AM, Adrian Bunk wrote:
> On Wed, Nov 07, 2012 at 05:33:54PM +0100, Stefano Lattarini wrote:
>> On 11/07/2012 04:41 PM, Paul Eggert wrote:
>>> On 11/07/2012 04:37 AM, Stefano Lattarini wrote:
>>>> I want to be able to assume the make recipes
>>>> are run by a POSIX shell.
>>>
>>> Thanks.
>>>
>>> Are all the features you're testing for specified by
>>> POSIX 1003.2-1992? (That is, are they all suitably *old* POSIX?)
>>>
>> I'm not really sure: I only looked at the last standard available
>> online on the Austing Group site:
>>
>> <http://pubs.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html>
>>
>> In any case, the features required seem common and simple enough, and
>> I'd rather start aiming a little high, and then lower our expectations
>> if we hit a real-world shell that doesn't support all the features
>> we are testing
>> ...
> 
> That sounds like a recipe for getting emergency 2.71, 2.72 and 2.73 
> releases, plus bad press as a bonus.

What we've done in the past is to do a release that probes for the new
features but does not mandate them, where the probe is quite verbal to
tell people to report the situation if the probe fails; then the next
release can actually start relying on the features.  (Remember how we
did it when we started requiring shell functions, for example).  That
is, autoconf 2.70 must provide the mechanisms for checking for a POSIX
shell, and even allow clients like automake to use those mechanisms to
require a POSIX shell, but autoconf itself won't require a POSIX shell
until 2.71 at the earliest, even though 2.70 is probing for one.

-- 
Eric Blake   address@hidden    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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