GNU bug report logs - #44525
Derivation of computed-file has no outputs

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Stefan <stefan-guix <at> vodafonemail.de>
To: bug-guix <at> gnu.org
Subject: Derivation of computed-file has no outputs
Date: Sun, 8 Nov 2020 21:19:36 +0100

Hi!

I try to use a computed-file as an input to a bootloader profile hook function. Using guix system I get this error message:

guix system: error: reference to invalid output 'out' of derivation '/gnu/store/946szbrwn3ja74yjnibbhjisjflvsk73-test.txt.drv'

This is the simple definition of the computed-file:

(computed-file "test.txt" (with-imported-modules '((guix utils)) #~(%current-system)))

And this is the content of the generated derivation of it:

Derive([],[("/gnu/store/0hcx4wgpgf1nn4gl3lhnd055vj2y28cj-guile-3.0.2.drv",["out"]),("/gnu/store/2ss1lzy0x0wwayy5n5mvzmsv77dnni39-module-import-compiled.drv",["out"])],["/gnu/store/9lw2pp0hjcjgmq5hx7w6aq92699r6pim-module-import","/gnu/store/plgbvrkkq1ghvph24kf0bdgb4w8glgqb-test.txt-builder"],"aarch64-linux","/gnu/store/x3gq648qnfnla7nppyfjvj62s2i8y7rl-guile-3.0.2/bin/guile",["--no-auto-compile","-L","/gnu/store/9lw2pp0hjcjgmq5hx7w6aq92699r6pim-module-import","-C","/gnu/store/3v6bh2hn62i4qp674d1hqg4ca7hpys3a-module-import-compiled","/gnu/store/plgbvrkkq1ghvph24kf0bdgb4w8glgqb-test.txt-builder"],[("preferLocalBuild","1")])

I think the problem is visible already with this call:

scheme@(guile-user)> (derivation-path->output-paths "/gnu/store/946szbrwn3ja74yjnibbhjisjflvsk73-test.txt.drv")
$5 = ()


Bye

Stefan

Message #8 received at 44525 <at> debbugs.gnu.org (full text, mbox):

From: Marius Bakke <marius <at> gnu.org>
To: Stefan <stefan-guix <at> vodafonemail.de>, 44525 <at> debbugs.gnu.org
Subject: Re: bug#44525: Derivation of computed-file has no outputs
Date: Sun, 08 Nov 2020 21:44:51 +0100

[Message part 1 (text/plain, inline)]

Stefan <stefan-guix <at> vodafonemail.de> writes:

> Hi!
>
> I try to use a computed-file as an input to a bootloader profile hook function. Using guix system I get this error message:
>
> guix system: error: reference to invalid output 'out' of derivation '/gnu/store/946szbrwn3ja74yjnibbhjisjflvsk73-test.txt.drv'

>
> This is the simple definition of the computed-file:
>
> (computed-file "test.txt" (with-imported-modules '((guix utils)) #~(%current-system)))

That's expected: this derivation does not produce any outputs.

Assuming you intended to write (%current-system) to test.txt, you can do
something along these lines:

  (computed-file "test.txt"
                 #~(call-with-output-file #$output
                     (lambda (port)
                       (format port #$(%current-system)))))

So I think this is not-a-bug.  WDYT?

[signature.asc (application/pgp-signature, inline)]

Message #11 received at 44525 <at> debbugs.gnu.org (full text, mbox):

From: Stefan <stefan-guix <at> vodafonemail.de>
To: Marius Bakke <marius <at> gnu.org>
Cc: 44525 <at> debbugs.gnu.org
Subject: Re: bug#44525: Derivation of computed-file has no outputs
Date: Mon, 9 Nov 2020 00:38:40 +0100

Hi Marius!

> Assuming you intended to write (%current-system) to test.txt, you can do
> something along these lines:
> 
>  (computed-file "test.txt"
>                 #~(call-with-output-file #$output
>                     (lambda (port)
>                       (format port #$(%current-system)))))

Thanks for this solution.

> That's expected: this derivation does not produce any outputs.
> So I think this is not-a-bug.  WDYT?


I think I got a bit distracted by the functionality of plain-file and the similar wording of the documentation of computed-file.

Thanks, I’ll close this issue.


Bye

Stefan

Message #16 received at 44525-done <at> debbugs.gnu.org (full text, mbox):

From: Stefan <stefan-guix <at> vodafonemail.de>
To: 44525-done <at> debbugs.gnu.org
Date: Mon, 9 Nov 2020 00:45:50 +0100

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