Re: Odd behavior with --dry-run and --upgrade

[Roel Janssen <roel@gnu.org>]

Ludovic Courtès writes:

> Roel Janssen <roel@gnu.org> skribis:
>
>> Ludovic Courtès writes:
>>
>>> Hi!
>>>
>>> Alex Kost <alezost@gmail.com> skribis:
>>>
>>>> Roel Janssen (2016-07-23 18:11 +0300) wrote:
>>>>
>>>>> Dear Guix,
>>>>>
>>>>> For some time now, running `guix package --dry-run --upgrade' results in
>>>>> build actions involving grafting.  For a dry-run, I find that really
>>>>> odd.  I believe the correct behavior should be what can be achieved
>>>>> with: `guix package --dry-run --no-grafts --upgrade'.
>>>>
>>>> I'm totally agree with this; nowadays I always use --dry-run with
>>>> --no-grafts option.
>>>
>>> Same here…
>>>
>>>> As a user I expect that --dry-run means no building at all.
>>>>
>>>> BTW it's not just about ‘guix package --dry-run --upgrade’, it relates
>>>> to all commands, for example ‘guix build --dry-run foo’, etc.
>>>>
>>>> OTOH, if a future ‘--dry-run’ would mean what ‘--dry-run --no-grafts’
>>>> means now, than how to achieve what ‘--dry-run’ means now?  Or rather:
>>>> does anyone use just --dry-run (without --no-grafts)?  Is it really
>>>> useful?
>>>
>>> In theory it could be useful for ‘guix build’, since it’s a “low level”
>>> tool and people using it may want to be able to distinguish between
>>> grafted and non-grafted results.
>>>
>>> But honestly, I think changing ‘--dry-run’ to do ‘--dry-run --no-grafts’
>>> would be fine, and probably better than the current situation.
>>
>> Could you provide some insight in where I should be looking to att the
>> check to 'graft?'?
>
> Everything that relates to command-line argument processing is in (guix
> scripts build), for the common options, and then in each (guix scripts
> *) module.
>
> Roughly, the change I suggest would be along these lines:
>

Aha.  Disabling grafting when the `--dry-run' switch is provided seems
like exactly what we want to do.  Should we add a `--enable-grafts' too?

> However, since --dry-run is processed separately in each command, this
> change should probably be duplicated.
>
> Would you like to look into it?

Yes!  Please allow me some time though.

> Something similar should be done in the Emacs interface.

I'm not familiar with the code of the Emacs interface.  Any other
takers for it?  Otherwise I will look into it, but that will take even
more time :)

Kind regards,
Roel Janssen