Rebuilding a package after removing a build step

Rebuilding a package after removing a build step

[Konrad Hinsen]

Hi everyone,

Until today, I thought that all parts of a package definition that could
make a difference to the outputs enter somehow into the package hash,
such that any relevant change to a package definition causes a rebuild.

Today's experience: I built a package, then removed an "add-after" form
from "modify-phases", effectively removing a build step, and ran "guix
build" again. It built nothing, and returned the same path (same hash)
as before.

Is this a bug or a feature? If it's a feature, how do I get Guix to
rebuild the package after removing a build step?

Cheers,
  Konrad.

Re: Rebuilding a package after removing a build step

[Tobias Geerinckx-Rice]

Hi Konrad,

'That is not possible.'  You must somehow not have measured what you thought you measured.

Probably not the answer you were looking for, but reassuring in its own way.

Can you 'reproduce' this?  It might still be enlightening to find out where things went wrong.

Kind regards,

T G-R

Sent on the go.  Excuse or enjoy my brevity.

Re: Rebuilding a package after removing a build step

[Konrad Hinsen]

Hi Tobias,

 Geerinckx-Rice <me@tobias.gr> writes:

> 'That is not possible.'  You must somehow not have measured what you thought you measured.

Thanks for restoring my faith in Guix!

You were in fact right, I was not measuring what I thought you measured,
but for an unusual reason.

> Can you 'reproduce' this?  It might still be enlightening to find out
> where things went wrong.

Yes, the behavior is perfectly reproducible. But it was tied to one
package definition. I tried modifying a few other definitions, with
expected outcomes.

So I set out to explore what is special about this package. It's a
definition I had started last week and came back to for finishing
touches. In the meantime, I had done a "guix pull", and with that update
I had retrieved an almost identical definition in the "guix" channel.
Someone else had beaten me to submitting the package!

Unfortunately, when there are several packages with identical name and
version number in two channels, Guix silently chooses one of them.
It would probably be more useful to emit a warning. So I ended up
editing a package definition which would undergo basic checking
by Guile, but then be ignored.

Cheers,
  Konrad.

Re: Rebuilding a package after removing a build step

[Suhail Singh]

Konrad Hinsen <konrad.hinsen@fastmail.net> writes:

> Unfortunately, when there are several packages with identical name and
> version number in two channels, Guix silently chooses one of them.

Ah, I had wondered what it did.  Thank you for reporting.

> It would probably be more useful to emit a warning.

Agreed.

On a related note, when multiple channels are enabled, is there a way to
specify a specific package from a particular channel?

-- 
Suhail

Re: Rebuilding a package after removing a build step

[Konrad Hinsen]

Suhail Singh <suhailsingh247@gmail.com> writes:

> On a related note, when multiple channels are enabled, is there a way to
> specify a specific package from a particular channel?

Yes, using the -e option followed by the Guile module name. See

  https://guix.gnu.org/manual/devel/en/html_node/Invoking-guix-package.html

You have to know the module and not just the channel.

Cheers,
  Konrad.

Re: Rebuilding a package after removing a build step

[Suhail Singh]

Konrad Hinsen <konrad.hinsen@fastmail.net> writes:

>> On a related note, when multiple channels are enabled, is there a way to
>> specify a specific package from a particular channel?
>
> Yes, using the -e option followed by the Guile module name. See
>
>   https://guix.gnu.org/manual/devel/en/html_node/Invoking-guix-package.html
>
> You have to know the module and not just the channel.

Thank you for the reference.

-- 
Suhail

Re: Rebuilding a package after removing a build step

[Felix Lechner via Development of GNU Guix and the GNU System distribution.]

Hi,

On Tue, Sep 17 2024, Tobias Geerinckx-Rice wrote:

> 'That is not possible.'

I believe I experienced it when removing or adding propagated or native
inputs (not sure) to my very own guile-pam [1] while using 'guix shell'.

Unfortunately, I have not had time to investigate.

Kind regards
Felix

[1] https://issues.guix.gnu.org/72316

P.S. Please excuse or enjoy my brevity.