customize-linux not working as expected

["dabbede@gmail.com" <dabbede@gmail.com>]

Dear community,

I would like to customize the configuration of my linux kernel, in
particular of a xenomai-patched one.
In the past days I've followed the route of using the procedure
make-linux-libre*, in particular using the
key  #:extra-options to append my customizations to
%default-extra-linux-options. In that case I did
not encounter any suspect behavior (except for the fact that
%default-extra-linux-options must be
appended after my list, and not the opposite, in order to have my
settings in place).

Today I've decided to give a try to the new procedure
"customize-linux". Here is the snippet:
----------------------------------------------------------------------------------------------------
define-public linux-xenomai
 (let ((father ((@@ (gnu packages linux) customize-linux)
            #:name "linux-xenomai"
            #:linux linux-libre-5.4
            #:defconfig "x86_64_defconfig"
            #:configs
            '("CONFIG_LOCALVERSION=\"-xenomai3.2.2\""
              ;; Xenomai specific tweaks
              "# CONFIG_SCHED_MC_PRIO is not set"
              "# CONFIG_CPU_FREQ is not set"
              "# CONFIG_ACPI_PROCESSOR is not set"
              "# CONFIG_CPU_IDLE is not set"
              "# CONFIG_APM is not set"
              "# CONFIG_INTEL_IDLE is not set"
              "# CONFIG_INPUT_PCSPKR is not set"
              "# CONFIG_COMPACTION is not set"
              "# CONFIG_MIGRATION is not set"
              ;; PCP customization
              "CONFIG_XENO_DRIVERS_NET=y"
              "CONFIG_XENO_DRIVERS_NET_DRV_E1000=m"
              "CONFIG_XENO_DRIVERS_NET_DRV_E1000E=m"
              "CONFIG_XENO_DRIVERS_NET_DRV_IGB=m"
              "CONFIG_NTFS_FS=m"
              "CONFIG_NTFS_RW=y"
              "CONFIG_CIFS=m"
              "CONFIG_CIFS_XATTR=y"
              "CONFIG_CONSOLE_LOGLEVEL_DEFAULT=4")))
       (ipipepatch (ipipe-x86-patch "5.4.228-x86-12"
"05l092vfswqlwyis0m6x5wa5hxwlmv7jwjpnjrbjav0b5ibv0xnr")))
 (package
   (inherit father)
   (name "linux-xenomai")
   (version "5.4.228")
   (arguments
     (substitute-keyword-arguments (package-arguments father)
          ((#:phases phases)
           #~(modify-phases #$phases
             (add-after 'unpack 'unpack-extra-sources
                (lambda _
                  (begin
                   (copy-recursively #+ipipepatch "ipipe.patch")
                   (copy-recursively #+xenomai-origin "xeno-source.tar.bz2")
                   (invoke "tar" "-xjf" "xeno-source.tar.bz2")
                   (invoke "bash" (string-append "xenomai-v"
#$xenomai-version "/scripts/prepare-kernel.sh") "--ipipe=ipipe.patch"
"--arch=x86_64"))))))))
   (synopsis "Linux kernel with Xenomai Cobalt co-kernel")
   (description
    "Xenomai is a Free Software project in which engineers from a wide
     background collaborate to build a robust and resource-efficient
     real-time core for Linux following the dual kernel approach, for
     applications with stringent latency requirements.")
   (home-page "http://xenomai.org/"))))
----------------------------------------------------------------------------------------------------

Unfortunately, some of my custom configs are in contrast to the
default one (and they have to be that
way for xenomai to work), and this leads the build process to stop at
"verify-config".
Here is the output to the terminal:
----------------------------------------------------------------------------------------------------
error: in phase 'configure': uncaught exception:
misc-error #f "~A ~S" ("Mismatching configurations in .config and
arch/x86/configs/guix_defconfig" (("CONFIG_JUMP_LABEL" (#f "y"))
("CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE" (#f "y"))
("CONFIG_CPU_FREQ_GOV_PERFORMANCE" (#f "y"))
("CONFIG_CPU_FREQ_GOV_ONDEMAND" (#f "y")) ("CONFIG_X86_ACPI_CPUFREQ"
(#f "y")) ("CONFIG_NF_CONNTRACK_IPV4" (#f "y"))
("CONFIG_IP_NF_TARGET_MASQUERADE" ("m" "y"))
("CONFIG_NF_CONNTRACK_IPV6" (#f "y")) ("CONFIG_SND_MIXER_OSS" (#f
"y")) ("CONFIG_SND_PCM_OSS" (#f "y")) ("CONFIG_SND_SEQUENCER_OSS" (#f
"y")) ("CONFIG_TIMER_STATS" (#f "y")) ("CONFIG_DEBUG_STACKOVERFLOW"
(#f "y")) ("CONFIG_XENO_DRIVERS_NET" ("m" "y")))) #f
phase `configure' failed after 111.5 seconds
Backtrace:
           8 (primitive-load "/gnu/store/9xgv231lklbbgfzxg3x002cgi42…")
In guix/build/gnu-build-system.scm:
    906:2  7 (gnu-build #:source _ #:outputs _ #:inputs _ #:phases . #)
In ice-9/boot-9.scm:
  1752:10  6 (with-exception-handler _ _ #:unwind? _ # _)
In srfi/srfi-1.scm:
    634:9  5 (for-each #<procedure 7ffff60565c0 at guix/build/gnu-b…> …)
In ice-9/boot-9.scm:
  1752:10  4 (with-exception-handler _ _ #:unwind? _ # _)
In guix/build/gnu-build-system.scm:
   927:23  3 (_)
In guix/build/kconfig.scm:
    174:6  2 (verify-config ".config" "arch/x86/configs/guix_defconf…")
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:
Mismatching configurations in .config and
arch/x86/configs/guix_defconfig (("CONFIG_JUMP_LABEL" (#f "y"))
("CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE" (#f "y"))
("CONFIG_CPU_FREQ_GOV_PERFORMANCE" (#f "y"))
("CONFIG_CPU_FREQ_GOV_ONDEMAND" (#f "y")) ("CONFIG_X86_ACPI_CPUFREQ"
(#f "y")) ("CONFIG_NF_CONNTRACK_IPV4" (#f "y"))
("CONFIG_IP_NF_TARGET_MASQUERADE" ("m" "y"))
("CONFIG_NF_CONNTRACK_IPV6" (#f "y")) ("CONFIG_SND_MIXER_OSS" (#f
"y")) ("CONFIG_SND_PCM_OSS" (#f "y")) ("CONFIG_SND_SEQUENCER_OSS" (#f
"y")) ("CONFIG_TIMER_STATS" (#f "y")) ("CONFIG_DEBUG_STACKOVERFLOW"
(#f "y")) ("CONFIG_XENO_DRIVERS_NET" ("m" "y")))
note: keeping build directory `/tmp/guix-build-linux-xenomai-5.4.228.drv-2'
builder for `/gnu/store/rdjhzffv8gdjrwm8y4kvqg8khzmc8qcz-linux-xenomai-5.4.228.drv'
failed with exit code 1
build of /gnu/store/rdjhzffv8gdjrwm8y4kvqg8khzmc8qcz-linux-xenomai-5.4.228.drv
failed
View build log at
'/var/log/guix/drvs/rd/jhzffv8gdjrwm8y4kvqg8khzmc8qcz-linux-xenomai-5.4.228.drv.gz'.
guix build: error: build of
`/gnu/store/rdjhzffv8gdjrwm8y4kvqg8khzmc8qcz-linux-xenomai-5.4.228.drv'
failed
----------------------------------------------------------------------------------------------------

This behaviour is strange to me, as I was expecting my #:configs to
take priority over default ones.

Am I missing something?!
Thank you for your support!