在GUIX中输入重写时如何使用劣质？

Question

郭氏下级手册指出

因此，您可以在任何地方插入一个劣质包:在清单中，在操作系统声明的packages字段中，等等。

但是，在重写包的输入时，我不知道如何使用劣值。例如，基于定义手册中的包变体部分的这个清单不适用于我：

(use-modules (guix inferior) (guix channels) (guix packages)
             (srfi srfi-1))
(use-package-modules docker)
(use-package-modules python-xyz)

(define mychannels
  (list (channel
         (name 'guix)
         (url "https://git.savannah.gnu.org/git/guix.git")
         ;; Last commit that still has python-pyyaml 5.4.1.
         (commit
          "d3e1a94391a838332b0565d56762a58cf87ac6b1"))))

(define myinferior
  (inferior-for-channels mychannels))

(define pyyaml5
  (first (lookup-inferior-packages myinferior "python-pyyaml")))


(define pyyaml5-instead-of-pyyaml6
  ;; This is a procedure to replace pyyaml 6.0 by pyyaml 5.4.1.

  ;; The line below does not work, raises this error:
  ;; In procedure package-properties: Wrong type argument:
  ;; #<inferior-package python-pyyaml@5.4.1 7f42653831b0>
  (package-input-rewriting `((,python-pyyaml . , pyyaml5)))

  ;; The line below does work (and has a similar result).
  ;(package-input-rewriting `((,python-pyyaml . , python-pyyaml-for-awscli)))
  )

(define docker-compose-with-pyyaml5
  (pyyaml5-instead-of-pyyaml6 docker-compose))

(packages->manifest
 (list pyyaml5
       (specification->package "python")
       docker-compose-with-pyyaml5
       ))

docker-compose只适用于python-pyyaml 5.4.1，通道中的版本已升级到6.0。因此，我试图进行的重写是将输入重写到docker-compose，以便使用通道的早期版本的python-pyyaml 5.4.1。然而，我的尝试失败了

Backtrace:
In guix/packages.scm:
  1269:17 19 (supported-package? #<package docker-compose@1.29.2 gu…> …)
In guix/memoization.scm:
    101:0 18 (_ #<hash-table 7fa05e6274c0 152/223> #<package docker…> …)
In guix/packages.scm:
  1247:37 17 (_)
  1507:16 16 (package->bag _ _ _ #:graft? _)
  1608:48 15 (thunk)
  1403:25 14 (inputs _)
In srfi/srfi-1.scm:
   586:29 13 (map1 (("python-cached-property" #<package python-…>) …))
   586:29 12 (map1 (("python-distro" #<package python-distro@1.…>) …))
   586:29 11 (map1 (("python-docker" #<package python-docker@5.…>) …))
   586:29 10 (map1 (("python-dockerpty" #<package python-docker…>) …))
   586:29  9 (map1 (("python-docopt" #<package python-docopt@0.…>) …))
   586:29  8 (map1 (("python-dotenv" #<package python-dotenv@0.…>) …))
   586:29  7 (map1 (("python-jsonschema" #<package python-jsons…>) …))
   586:17  6 (map1 (("python-pyyaml" #<package python-pyyaml@6.…>) …))
In guix/packages.scm:
  1360:20  5 (rewrite ("python-pyyaml" #<package python-pyyaml@6.0…>))
In guix/memoization.scm:
    101:0  4 (_ #<hash-table 7fa06ac0b540 8/31> #<package python-py…> …)
In guix/packages.scm:
  1377:22  3 (_)
  1435:37  2 (loop #<inferior-package python-pyyaml@5.4.1 7fa06304b3…>)
In ice-9/boot-9.scm:
  1685:16  1 (raise-exception _ #:continuable? _)
  1685:16  0 (raise-exception _ #:continuable? _)

ice-9/boot-9.scm:1685:16: In procedure raise-exception:
In procedure package-properties: Wrong type argument: #<inferior-package python-pyyaml@5.4.1 7fa06304b3f0>

我怎么能用低劣的方式重写输入呢？

显然，现在频道中有一个名为python-pyyaml 5.4.1的python-pyyaml-for-awscli。使用该包重写docker-compose的输入确实像预期的那样工作，因此，据我所知，在重写输入时，我使用了正确的语法。(我不知道背勾、点和逗号是怎么回事，可能是哪里出错了。)

(至于XY问题，我现在可以使用docker-compose运行python-pyaml-for-awscli，但是我仍然对如何使用劣等程序感兴趣，因为接下来可能没有这样的包。)

Answer 1

显然，现在Guix1.3.0中还没有一个modify-inputs函数，我不知道是否有可以链接到的“夜间”文档。

这样做是可行的：

(use-modules (guix inferior) (guix channels) (guix packages)
             (srfi srfi-1))
(use-package-modules docker)
(use-package-modules python-xyz)

(define mychannels
  (list (channel
         (name 'guix)
         (url "https://git.savannah.gnu.org/git/guix.git")
         ;; Last commit with pyyaml 5.4.1.
         (commit
          "d3e1a94391a838332b0565d56762a58cf87ac6b1"))))

(define myinferior
  (inferior-for-channels mychannels))

(define pyyaml5
  (first (lookup-inferior-packages myinferior "python-pyyaml")))


(define (also-pyyaml5-instead-of-pyyaml6 apackage)
  ;; This is a procedure to replace pyyaml 6.0 by pyyaml 5.4.1.
  (package
   (inherit apackage)
   (inputs
    (modify-inputs (package-inputs apackage)
                   (replace "python-pyyaml" pyyaml5)))))

(define also-docker-compose-with-pyyaml5
  (also-pyyaml5-instead-of-pyyaml6 docker-compose))

(packages->manifest
 (list python-pyyaml
       (specification->package "python")
       also-docker-compose-with-pyyaml5))

现在，docker-compose使用python-pyyaml的5.4.1版本，而配置文件的其余部分使用6.0。

我仍然不清楚是否可以在package-input-rewriting中使用下位用户，但是使用modify-inputs实现了同样的目的，而且它是有效的。