* doc/guix.texi (Invoking guix deploy): Add section describing the
'build-locally?' field of 'managed-host-environment-type'.

* guix/ssh.scm (remote-authorize-signing-key): New variable.
* gnu/machine/ssh.scm (deploy-managed-host): Authorize coordinator's
signing key before any invocations of 'remote-eval'.
(deploy-managed-host): Display an error if a signing key does not exist.
* doc/guix.texi (Invoking guix deploy): Remove section describing manual
signing key authorization.
(Invoking guix deploy): Add section describing the 'authorize?' field.

* doc/guix.texi (Invoking guix deploy): Add section describing
prerequisites for deploying as a non-root user.
* guix/remote.scm (remote-pipe-for-gexp): New optional 'become-command'
argument.
(%remote-eval): New optional 'become-command' argument.
(remote-eval): New 'become-command' keyword argument.
* guix/ssh.scm (remote-inferior): New optional 'become-command'
argument.
(inferior-remote-eval): New optional 'become-command' argument.
(remote-authorize-signing-key): New optional 'become-command' argument.
* gnu/machine/ssh.scm (machine-become-command): New variable.
(managed-host-remote-eval): Invoke 'remote-eval' with the
'#:become-command' keyword.
(deploy-managed-host): Invoke 'remote-authorize-signing-key' with the
'#:become-command' keyword.

* gnu/machine/ssh.scm (machine-ssh-configuration): Add 'system' field.
(managed-host-remote-eval): Pass 'system' field to 'remote-eval'.
(machine-check-building-for-appropriate-system): New variable.
(check-deployment-sanity): Add call to
'machine-check-building-for-appropriate-system'.
* doc/guix.texi (Invoking guix deploy): Describe new 'system' field.
* guix/ssh.scm (remote-system): New variable.
* guix/remote.scm (remote-eval): Use result of 'remote-system' when
lowering the G-Expression.
(remote-eval): Add 'system' keyword argument.
(trampoline): Return a <program-file> rather than a <scheme-file>.

* gnu/machine.scm (machine-system): Delete variable.
(machine-operating-system): New variable.
All callers changed.
* doc/guix.texi (Invoking guix deploy): Use the
'machine-operating-system' accessor rather than 'machine-system'.

* doc/guix.texi (Invoking guix deploy): Add note explaining that
deployment targets must authorize the coordinator machine's signing key.

* guix/build/cargo-build-system.scm (generate-all-checksums): New
procedure.
(update-cargo-lock, patch-cargo-checksums): New phases.
(%standard-phases): Add 'update=cargo-lock after 'configure and
'patch-cargo-checksums after 'patch-generated-file-shebangs.
* doc/guix.texi (Build System)[cargo-build-system]: Mention how
Cargo.lock files are handled.

Fixes <https://bugs.gnu.org/36813>.
Reported by Jakob L. Kreuze <zerodaysfordays.sdf.org@sdf.org>.

* guix/gexp.scm (program-file-compiler): Pass #:system and #:target to
'gexp->script'.
(load-path-expression): Add #:system and #:target and honor them.
(gexp->script): Likewise.
* tests/gexp.scm ("program-file #:system"): New test.
* doc/guix.texi (G-Expressions): Adjust accordingly.

Fixes <https://bugs.gnu.org/36371>.
Reported by Tobias Geerinckx-Rice <me@tobias.gr>.

* guix/git.scm (git-checkout-compiler): Pass 'tag-or-commit' to
'latest-repository-commit*'.
* doc/guix.texi (Package Transformation Options): Update '--with-commit'
documentation accordingly.
* tests/guix-build-branch.sh: Add test.

Guile-JSON 3.x is incompatible with Guile-JSON 1.x, which we relied on
until now: it maps JSON dictionaries to alists (instead of hash tables),
and JSON arrays to vectors (instead of lists).  This commit is about
adjusting all the existing code to this new mapping.

* m4/guix.m4 (GUIX_CHECK_GUILE_JSON): New macro.
* configure.ac: Use it.
* doc/guix.texi (Requirements): Mention the Guile-JSON version.
* guix/git-download.scm (git-fetch)[guile-json]: Use GUILE-JSON-3.
* guix/import/cpan.scm (string->license): Expect vectors instead of
lists.
(module->dist-name): Use 'json-fetch' instead of 'json-fetch-alist'.
(cpan-fetch): Likewise.
* guix/import/crate.scm (crate-fetch): Likewise, and call 'vector->list'
for DEPS.
* guix/import/gem.scm (rubygems-fetch): Likewise.
* guix/import/json.scm (json-fetch-alist): Remove.
* guix/import/pypi.scm (pypi-fetch): Use 'json-fetch' instead of
'json-fetch-alist'.
(latest-source-release, latest-wheel-release): Call 'vector->list' on
RELEASES.
* guix/import/stackage.scm (stackage-lts-info-fetch): Use 'json-fetch'
instead of 'json-fetch-alist'.
(lts-package-version): Use 'vector->list'.
* guix/import/utils.scm (hash-table->alist): Remove.
(alist->package): Pass 'vector->list' on the inputs fields, and default
to the empty vector.
* guix/scripts/import/json.scm (guix-import-json): Remove call to
'hash-table->alist'.
* guix/swh.scm (define-json-reader): Expect pair? or null? instead of
hash-table?.
[extract-field]: Use 'assoc-ref' instead of 'hash-ref'.
(json->branches): Use 'map' instead of 'hash-map->list'.
(json->checksums): Likewise.
(json->directory-entries, origin-visits): Call 'vector->list' on the
result of 'json->scm'.
* tests/import-utils.scm ("alist->package with dependencies"): New test.
* gnu/installer.scm (build-compiled-file)[builder]: Use GUILE-JSON-3.
* gnu/installer.scm (installer-program)[installer-builder]: Likewise.
* gnu/installer/locale.scm (iso639->iso639-languages): Use 'assoc-ref'
instead of 'hash-ref', and pass vectors through 'vector->list'.
(iso3166->iso3166-territories): Likewise.
* gnu/system/vm.scm (system-docker-image)[build]: Use GUILE-JSON-3.
* guix/docker.scm (manifest, config): Adjust for Guile-JSON 3.
* guix/scripts/pack.scm (docker-image)[build]: Use GUILE-JSON-3.
* guix/import/github.scm (fetch-releases-or-tags): Update docstring.
(latest-released-version): Use 'assoc-ref' instead of 'hash-ref'.  Pass
the result of 'fetch-releases-or-tags' to 'vector->list'.
* guix/import/launchpad.scm (latest-released-version): Likewise.