* guix/scripts/build.scm (%default-options): Remove 'system'.
(%options) <--system>: Keep previous occurrences of 'system in RESULT.
(options->derivations)[system]: Remove.
[systems, things-to-build]: New variables.
[compute-derivation]: New procedure.
Iterate on all of SYSTEMS to compute the derivations of THINGS-TO-BUILD.
* tests/guix-build.sh: Add test for one and multiple '-s' flags.
* doc/guix.texi (Additional Build Options): Document this behavior.

Suggested by pkill9 <pkill9@runbox.com>.

* guix/scripts/pull.scm (channel-list): Apply REF and URL to the 'guix'
channel.
* doc/guix.texi (Invoking guix pull): Adjust accordingly.

* doc/guix.texi (Hardware Considerations, Service Types and Services)
(Service Reference, Shepherd Services, Security Updates): Use @code
instead of @var for things that are not meta-syntactic variables.

* doc/guix.texi (package Reference): Document 'this-package'.
(operating-system Reference): Document 'this-operating-system'.

* gnu/system.scm (<operating-system>)[label]: New field.
(operating-system-default-label): New procedure.
(operating-system-boot-parameters): Use it instead of
'kernel->boot-label'.
* doc/guix.texi (operating-system Reference): Document it.

* doc/guix.texi (Miscellaneous Services): Correct module name.

Follow-up to 96ef8565.

* doc/guix.texi (Limitations): Fix typo.

* doc/guix.texi (Limitations): Strip the paragraph about not being
production-ready.  Remove the number of packages.

* guix/build/linux-module-build-system.scm: New file.
* guix/build-system/linux-module.scm: New file.
* doc/guix.texi (Build Systems): Document it.
* Makefile.am (MODULES): Add them.

* doc/guix.texi (Bootloader Configuration): Fix ‘fow now’.

* guix/scripts/gc.scm (show-help, %options): Add
'--delete-generations'.  Change '--delete' shorthand to '-D'.
(delete-old-generations): New procedure.
(guix-gc)[delete-generations]: New procedure.
Call it when ACTION is 'collect-garbage' and OPTS contains
'delete-generations.
* doc/guix.texi (Invoking guix gc): Document it.

* guix/scripts/gc.scm (show-help, %options): Add '--list-roots'.
(guix-gc)[list-roots]: New procedure.
Handle '--list-roots'.
* tests/guix-gc.sh: Test it.
* doc/guix.texi (Invoking guix gc): Document it.

This is a followup to 412e6396.

* doc/guix.texi (Mail Services): Fix syntax of cross-references to the
Mailutils manual.

* gnu/services/mail.scm (<imap4d-configuration>): New record type.
(imap4d-shepherd-service): New procedure.
(%default-imap4d-config-file, imap4d-service-type): New variables.
* gnu/services/mail.scm (Mail Services): Document it.

* gnu/services/base.scm (console-keymap-service): Mark as deprecated.
* doc/guix.texi (Base Services): Remove its documentation.

* doc/guix.texi (Keyboard Layout): Mention GNOME's "Region & Language",
setxkbmap, and loadkeys.

* gnu/services/xorg.scm (gdm-service-type)[compose, extend]: New fields.
(set-xorg-configuration): New procedure.
* doc/guix.texi (Keyboard Layout): Use it.
(X Window): Document it.
* gnu/system/examples/desktop.tmpl: Add 'keyboard-layout' fields.

* guix/scripts/environment.scm (launch-environment/container): Add UID
and GID.  Use them in PASSWD and GROUPS.  Pass them as #:guest-uid and
 #:guest-gid to 'call-with-container'.
* tests/guix-environment-container.sh: Test the inner UID.
In '--user' test, replace hard-coded 0 with 1000.
* doc/guix.texi (Invoking guix environment): Adjust accordingly.

* doc/guix.texi (X Window): Document 'gdm-service-type' and
'gdm-configuration'.  Take description of '.desktop' files from the
'slim-service-type' description.
* gnu/services/xorg.scm (gdm-service): Remove outdated comment.

This field has become unnecessary with the addition of 'this-package'.

* guix/packages.scm (<package>)[self-native-input?]: Remove.
(package->bag): Adjust accordingly.
* doc/guix.texi (package Reference): Remove 'self-native-input?'.

* doc/guix.texi (Invoking guix pull): Use @xref instead of @ref at the
beginning of sentences.

* gnu/services/desktop.scm (%desktop-services): Replace
SLIM-SERVICE-TYPE instance with an instance of GDM-SERVICE-TYPE.
* doc/guix.texi (Keyboard Layout): Change example to mention
GDM-SERVICE-TYPE.
(X Window): Mention GDM.
(Desktop Services): Adjust references to SLiM.

* gnu/services/desktop.scm (xfce-desktop-service-type)[default-value]
[description]: New fields.
(xfce-desktop-service): Deprecate.
* gnu/system/examples/desktop.tmpl: Use the (service …) form.
* gnu/installer/services.scm (%desktop-environments): Add TODO comment.
* doc/guix.texi (Desktop Services): Adjust accordingly, and fix spelling
of "Xfce" throughout.

* gnu/services/desktop.scm (gnome-desktop-service-type)[default-value]:
New field.
(gnome-desktop-service): Deprecate.
* gnu/installer/services.scm (%desktop-environments): Use the (service …)
form for GNOME.
* gnu/system/examples/desktop.tmpl: Likewise.
* doc/guix.texi (Desktop Services): Adjust accordingly.

* gnu/system.scm (<operating-system>)[essential-services]: New field.
(operating-system-directory-base-entries): Remove #:container? keyword
and keep only the not-container branch.
(essential-services): Likewise.
(operating-system-services): Likewise, and call
'operating-system-essential-services' instead of 'essential-services'.
(operating-system-activation-script): Remove #:container?.
(operating-system-boot-script): Likewise.
(operating-system-derivation): Likewise.
* gnu/system/linux-container.scm (container-essential-services): New procedure.
(containerized-operating-system): Use it and set the
'essential-services' field.
(container-script): Remove call to 'operating-system-derivation'.
* gnu/system/vm.scm (system-docker-image): Likewise.
* doc/guix.texi (operating-system Reference): Document 'essential-services'.

* gnu/system/accounts.scm (<user-account>)[home-directory]: Mark as
thunked and add a default value.
(default-home-directory): New procedure.
* doc/guix.texi (User Accounts): Remove 'home-directory' from example.
* gnu/system/examples/bare-bones.tmpl: Likewise.
* gnu/system/examples/beaglebone-black.tmpl: Likewise.
* gnu/system/examples/desktop.tmpl: Likewise.
* gnu/system/examples/docker-image.tmpl: Likewise.
* gnu/system/examples/lightweight-desktop.tmpl: Likewise.
* gnu/system/install.scm (installation-os): Likewise.
* gnu/tests.scm (%simple-os): Likewise.
* gnu/tests/install.scm (%minimal-os, %minimal-os-on-vda):
(%separate-home-os, %encrypted-root-os, %btrfs-root-os): Likewise.
* tests/accounts.scm ("allocate-passwd")
("allocate-passwd with previous state"): Likewise.

* doc/guix.texi (Keyboard Layout): New node.
(Bootloader Configuration): Remove examples and refer to it.
(X Window): Add cross-reference.

Partially fixes <https://bugs.gnu.org/25453>.

* gnu/system.scm (<operating-system>)[keyboard-layout]: New field.
(operating-system-initrd-file): Pass #:keyboard-layout to MAKE-INITRD.
* gnu/system/linux-initrd.scm (raw-initrd): Add #:keyboard-layout.
Pass #:keymap-file to 'boot-system'.
(base-initrd): Add #:keyboard-layout.
[helper-packages]: Add LOADKEYS-STATIC when KEYBOARD-LAYOUT is true.
Pass #:keyboard-layout to 'raw-initrd'.
* gnu/build/linux-boot.scm (boot-system): Add #:keymap-file and honor
it.
* doc/guix.texi (operating-system Reference): Document the
'keyboard-layout' field.
(Initial RAM Disk): Update 'raw-initrd' and 'base-initrd' documentation.

* gnu/services/xorg.scm (<xorg-configuration>)[keyboard-layout]: New
field.
(xorg-configuration->file)[input-class-section]: New procedure.
Use it.
* doc/guix.texi (X Window): Document 'keyboard-layout' field.

Co-authored-by: nee <nee-git@hidamari.blue>

* gnu/services/sddm.scm (<sddm-configuration>)[xorg-server-path]
[xserver-arguments]: Remove.
[xorg-configuration]: New field.
(sddm-configuration-file): Adjust accordingly.
* gnu/services/xorg.scm (<slim-configuration>)[startx]: Remove.
[xorg-configuration]: New field.
(slim-shepherd-service, slim-service): Adjust accordingly.
(<gdm-configuration>)[x-server]: Remove.
[xorg-configuration]: New field.
(gdm-shepherd-service, gdm-service): Adjust accordingly.
* doc/guix.texi (X Window): Update accordingly.

* gnu/services/xorg.scm (<xorg-configuration>): New record type.
(xorg-configuration-file): Remove.
(xorg-wrapper): Remove #:modules, #:configuration-file, and
 #:xorg-server; add optional 'config' parameter instead.  Adjust
accordingly.
(xorg-start-command): Likewise.
* doc/guix.texi (X Window): Document 'xorg-configuration'.  Update
'xorg-start-command' documentation.  Remove 'xorg-configuration-file'
documentation.

* gnu/services/xorg.scm (xorg-wrapper): Remove #:guile, which was unused.
(xorg-start-command): Likewise.
(xinitrc): Likewise.

* gnu/bootloader/grub.scm (keyboard-layout-file): New procedure.
(grub-configuration-file)[keyboard-layout-file]: New variable.
[builder]: Use it.
* gnu/bootloader.scm (<bootloader-configuration>)[keyboard-layout]: New
field.
* doc/guix.texi (Bootloader Configuration): Document it.

Co-authored-by: nee <nee-git@hidamari.blue>

* doc/contributing.texi (Submitting Patches): Remove powerpc-linux
examples.
* doc/guix.texi (Virtualization Services): Replace powerpc-linux example
with mips64el-linux.

* guix/build-system/dune.scm: Add a package parameter.
* guix/build/dune.scm (build, test, install): Use it.
* doc/guix.texi: Document it.

* guix/build-system/rakudo.scm,
guix/build/rakudo-build-system.scm: New files.
* Makefile.am (MODULES): Add them.
* doc/guix.texi (Build System): Document it.

Suggested by Julien Lepiller.

* guix/scripts/graph.scm (%reverse-bag-node-type): New variable.
(%node-types): Add it.
* tests/graph.scm ("reverse bag DAG"): New test.
* doc/guix.texi (Invoking guix graph): Document it.

* gnu/services/authentication.scm (nslcd-service-type, nslcd-configuration,
%nslcd-accounts): New variables.
(uglify-field-name, value->string, serialize-field, serialize-list,
ssl-option?, tls-reqcert-option?, deref-option?,
comma-separated-list-of-strings?, serialize-ignore-users-option, log-option?,
serialize-log-option, valid-map?, scope-option?, serialize-scope-option,
map-entry?, list-of-map-entries?, filter-entry?, list-of-filter-entries?,
serialize-filter-entry, serialize-list-of-filter-entries, serialize-map-entry,
serialize-list-of-map-entries, nslcd-config-file, nslcd-etc-service,
nslcd-shepherd-service, pam-ldap-pam-services, pam-ldap-pam-service,
generate-nslcd-documentation): New procedures.
* gnu/tests/ldap.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.
* doc/guix.texi (LDAP Services): Document it.

* guix/import/launchpad.scm: New file.
* Makefile.am (MODULES): Register it.
* doc/guix.texi (Invoking guix refresh): Mention the Launchpad updater.