[PATCH 0/1] qt-build-system: Wrap with build variables to allow %outputs in arguments

[PATCH 0/1] qt-build-system: Wrap with build variables to allow %outputs in arguments

[Rutherther]

It is impossible to refer to %outputs in arguments like #:configure-flags
(ie. `(assoc-ref %outputs "out")` leads to unbound-variable %outputs).
I think the issue is in qt using different system than build systems such
as cmake or gnu. Since I am unsure about the reason for qt not having
the same structure, I am submitting this to guix devel for discussion,
as well as opening a patch in case this is fine to be merged. If not,
could someone please explain what the reason behind not adding
inputs and outputs is, and what is the alternative?

Regards,
Rutherther

Rutherther (1):
  guix: qt: add inputs and outputs build variables in qt-build

 guix/build-system/qt.scm | 54 +++++++++++++++++++++-------------------
 1 file changed, 28 insertions(+), 26 deletions(-)


base-commit: 006679d1e6ca7acea0629b4f019c8cf89cde08be
--
2.46.0

Re: [PATCH 0/1] qt-build-system: Wrap with build variables to allow %outputs in arguments

[John Kehayias via Development of GNU Guix and the GNU System distribution.]

Hi Rutherther,

On Wed, Dec 04, 2024 at 11:17 PM, Rutherther wrote:

> It is impossible to refer to %outputs in arguments like #:configure-flags
> (ie. `(assoc-ref %outputs "out")` leads to unbound-variable %outputs).

You should be able to use gexps, e.g. #$output (see
<https://guix.gnu.org/manual/devel/en/html_node/G_002dExpressions.html>
for more details). That is actually the preferred way now, though
there are still instances of assoc-ref.

I believe the commit in question is
<https://git.savannah.gnu.org/cgit/guix.git/commit?id=7d873f194ca69d6096d28d7a224ab78e83e34fe1>.

> I think the issue is in qt using different system than build systems such
> as cmake or gnu. Since I am unsure about the reason for qt not having
> the same structure, I am submitting this to guix devel for discussion,
> as well as opening a patch in case this is fine to be merged. If not,
> could someone please explain what the reason behind not adding
> inputs and outputs is, and what is the alternative?
>

Though perhaps you are getting at that you'd expect the older way to
still work? Perhaps qt-build purposefully left the older procedure
behind as it should have much fewer dependents (which may rely on the
old assoc-ref)?

Hope that helps! The short of it is to use gexps :)

John

Re: [PATCH 0/1] qt-build-system: Wrap with build variables to allow %outputs in arguments

[Rutherther]

Hi John,
thanks.

> You should be able to use gexps, e.g. #$output (see
> <https://guix.gnu.org/manual/devel/en/html_node/G_002dExpressions.html>
> for more details). That is actually the preferred way now, though
> there are still instances of assoc-ref.

> I believe the commit in question is
> <https://git.savannah.gnu.org/cgit/guix.git/commit?id=7d873f194ca69d6096d28d7a224ab78e83e34fe1>.

I've seen this commit before and saw that many of the build systems
in it had the inputs and outputs build variables added, so that's why I asked.

> Though perhaps you are getting at that you'd expect the older way to
> still work? Perhaps qt-build purposefully left the older procedure
> behind as it should have much fewer dependents (which may rely on the
> old assoc-ref)?

Yes, exactly, I wanted to know if this is purposefully left out, ie. for
the thing you are saying - less dependants, or if it was sort of a
mistake.

So is the goal to port everything to gexps eventually, and to get
rid of %outputs completely? 

Regards,
Rutherther