bug#38529: Make --pure the default for `guix environment'?

[Christopher Lemmer Webber <cwebber@dustycloud.org>]

Taylan Kammer writes:

> On 10.12.2019 18:16, Ludovic Courtès wrote:
>> Hello!
>> "Thompson, David" <dthompson2@worcester.edu> skribis:
>> 
>>> I have long thought that --ad-hoc should be implied, as that is the
>>> mode I use 99% of the time, but I disagree that --pure should be the
>>> default.
>> I very much agree with that.  I don’t think ‘--pure’ should be the
>> default, because there are valid use cases for that.
>> As for ‘--ad-hoc’: making it the default is technically easy.  The
>> difficulty is to come up with a nice transition/deprecation mechanism so
>> that we don’t break everyone’s script overnight.
>> Ideas on how to achieve it are welcome!
>> Thanks,
>> Ludo’.
>> 
>
> I suppose the straightforward way of doing such a transition would be:
>
> - In the next release, add --inputs-of and make the use of 'guix
>   environment' with neither switch emit a warning saying you should
>  use the new switch to explicitly enable it because the default will
> change.
>
> - Later, change the default behavior and deprecate --ad-hoc as it
>   becomes a no-op.
>
> - (Optional) In some future release, remove --ad-hoc.
>
>
> Taylan

That sounds good to me.

And could we make "env" a shortcut for "environment" anyway?  My fingers
are tired. ;)