I don't think this is the right fix. Now you define packages with the incorrect url-fetch, so the test passes, but package->code would still not work as intended on actual packages that are properly defined.

It seems that the issue is package->code uses the internal name url-fetch* whereas it should be the exported name url-fetch. I think this is a legitimate bug in package->code and your patch incorrectly hides it.

Le 24 mars 2021 21:44:37 GMT-04:00, "Léo Le Bouter via Bug reports for GNU Guix" <bug-guix@gnu.org> a écrit :
>FAIL: tests/print
>=================
>
>test-name: simple package
>location: /tmp/guix-build-guix-1.2.0-18.86dd54f.drv-
>0/source/tests/print.scm:70
>source:
>+ (test-equal
>+   "simple package"
>+   `(define-public test ,pkg-source)
>+   (package->code pkg))
>expected-value: (define-public test (package (name "test") (version
>"1.2.3") (source (origin (method url-fetch) (uri (string-append
>"file:///tmp/test-" version ".tar.gz")) (sha256 (base32
>"070pwb7brdcn1mfvplkd56vjc7lbz4iznzkqvfsakvgbv68k71ah")))) (build-
>system (@ (guix build-system gnu) gnu-build-system)) (home-page "
>http://gnu.org") (synopsis "Dummy") (description "This is a dummy
>package.") (license license:gpl3+)))
>actual-value: (define-public test (package (name "test") (version
>"1.2.3") (source (origin (method url-fetch*) (uri (string-append
>"file:///tmp/test-" version ".tar.gz")) (sha256 (base32
>"070pwb7brdcn1mfvplkd56vjc7lbz4iznzkqvfsakvgbv68k71ah")))) (build-
>system (@ (guix build-system gnu) gnu-build-system)) (home-page "
>http://gnu.org") (synopsis "Dummy") (description "This is a dummy
>package.") (license license:gpl3+)))
>result: FAIL
>
>test-name: package with inputs
>location: /tmp/guix-build-guix-1.2.0-18.86dd54f.drv-
>0/source/tests/print.scm:74
>source:
>+ (test-equal
>+   "package with inputs"
>+   `(define-public test ,pkg-with-inputs-source)
>+   (package->code pkg-with-inputs))
>expected-value: (define-public test (package (name "test") (version
>"1.2.3") (source (origin (method url-fetch) (uri (string-append
>"file:///tmp/test-" version ".tar.gz")) (sha256 (base32
>"070pwb7brdcn1mfvplkd56vjc7lbz4iznzkqvfsakvgbv68k71ah")))) (build-
>system (@ (guix build-system gnu) gnu-build-system)) (inputs
>(quasiquote (("coreutils" (unquote (@ (gnu packages base) coreutils)))
>("glibc" (unquote (@ (gnu packages base) glibc)) "debug")))) (home-page
>
>"http://gnu.org") (synopsis "Dummy") (description "This is a dummy
>package.") (license license:gpl3+)))
>actual-value: (define-public test (package (name "test") (version
>"1.2.3") (source (origin (method url-fetch*) (uri (string-append
>"file:///tmp/test-" version ".tar.gz")) (sha256 (base32
>"070pwb7brdcn1mfvplkd56vjc7lbz4iznzkqvfsakvgbv68k71ah")))) (build-
>system (@ (guix build-system gnu) gnu-build-system)) (inputs
>(quasiquote (("coreutils" (unquote (@ (gnu packages base) coreutils)))
>("glibc" (unquote (@ (gnu packages base) glibc)) "debug")))) (home-page
>
>"http://gnu.org") (synopsis "Dummy") (description "This is a dummy
>package.") (license license:gpl3+)))
>result: FAIL
>
>Full log: https://ci.guix.gnu.org/build/117996/log/raw
>
>Seems related to f7008ca71351e5368a7c1c5bc3fe88fb80b01298
>
>This patch fixes the issue but I am not sure it retains the test's
>original intent:
>
>diff --git a/tests/print.scm b/tests/print.scm
>index 3386590d3a..85735cf9ae 100644
>--- a/tests/print.scm
>+++ b/tests/print.scm
>@@ -19,7 +19,7 @@
> (define-module (test-print)
>   #:use-module (guix import print)
>   #:use-module (guix build-system gnu)
>-  #:use-module (guix download)
>+  #:use-module (guix build download)
>   #:use-module (guix packages)
>   #:use-module ((guix licenses) #:prefix license:)
>   #:use-module (srfi srfi-64))
>
>Let me know!
>
>Thank you