bug#67221: Package identity transformation produces different derivation

bug#67221: Package identity transformation produces different derivation

[Ulf Herrman]

[-- Attachment #1: Type: text/plain, Size: 799 bytes --]

$ guix build --no-grafts --derivations -e \
     '(begin
       (use-modules (guix packages) (gnu packages gtk))
       ((package-mapping identity) cairo-sans-poppler))' \
       -e '(@ (gnu packages gtk) cairo-sans-poppler)'
=>
/gnu/store/51hwf2mc2ig76a3nm86msv4z9az3s0j3-cairo-1.16.0.drv
/gnu/store/q78ziqcg2dvi2lzj18hzdld85bcydzwk-cairo-1.16.0.drv

Some interesting notes:

1. (package-mapping identity #:deep? #t) *does* produce the same
   derivation.
2. bag->derivation's `delete-duplicates' call uses `input=?', but its
   input objects in the second tuple position are all <gexp-input>s
   produced by `expand-input'.  Consequently, `input=?' will fall back
   to using `equal?' instead of `derivation=?'.  I don't know to what
   extent this has to do with the observed bug.

- ulfvonbelow

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 686 bytes --]

bug#67221: Package identity transformation produces different derivation

[Simon Tournier]

Hi,

On Wed, 15 Nov 2023 at 21:56, Ulf Herrman <striness@tilde.club> wrote:
> $ guix build --no-grafts --derivations -e \
>      '(begin
>        (use-modules (guix packages) (gnu packages gtk))
>        ((package-mapping identity) cairo-sans-poppler))' \
>        -e '(@ (gnu packages gtk) cairo-sans-poppler)'
> =>
> /gnu/store/51hwf2mc2ig76a3nm86msv4z9az3s0j3-cairo-1.16.0.drv
> /gnu/store/q78ziqcg2dvi2lzj18hzdld85bcydzwk-cairo-1.16.0.drv

The only difference is from the builder: %build-inputs contains

   ("util-linux" . "/gnu/store/gwx2sf5wl9bsl21lwv35g5la63bwyy95-util-linux-2.37.4-lib")

for the non-transformed ’(@ (gnu packages gtk) cairo-sans-poppler)’
package, only.

Hum, is ’package-mapping’ removing it?


> 1. (package-mapping identity #:deep? #t) *does* produce the same
>    derivation.

Well, it means that #:deep? #t adds “util-linux” in the builder.


Cheers,
simon