scripts: system: Back out operating-system-bootcfg change.

Follow-up to 475e2ce211ac05a814c1f1bc2b9648baa17ad369.

* guix/scripts/system.scm (perform-action): Back out operating-system-bootcfg
change.

scripts: system: Move save-load-path-excursion and save-environment-excursion macros to the top.

* guix/scripts/system.scm (save-load-path-excursion,
save-environment-excursion): Move definitions to the top of the file.
It allows to use them in the whole file.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

scripts: system: Move save-load-path-excursion and save-environment-excursion macros to the top.

* guix/scripts/system.scm (save-load-path-excursion,
save-environment-excursion): Move definitions to the top of the file.
It allows to use them in the whole file.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

pack: Add '--expression'.

* guix/scripts/pack.scm (%options, show-help): Add '--expression'.
(guix-pack)[maybe-package-argument]: New procedure.
Use it, and remove variable 'specs'.
* doc/guix.texi (Invoking guix pack): Document '--expression'.

size: Avoid '_' as a pattern variable in 'match'.

* guix/scripts/size.scm (display-profile, profile->page-map): Don't use
'_' as a 'match' pattern variable.

system: Support the --root option in 'guix system'.

Fixes <https://bugs.gnu.org/26271>.

* guix/scripts/system.scm (perform-action): Add #:gc-root parameter and
honor it.
(show-help): Document the --root option.
(%options): Add 'root'.
(process-action): Pass 'root' option to perform-action as #:gc-root.
* doc/guix.texi (Invoking guix system): Document '--root'.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

build: Add and export procedure 'register-root*'.

* guix/scripts/build.scm (register-root*): Add and export it.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

environment: Deal with single-entry search paths.

This is a followup to fcd75bdbfa99d14363b905afbf914eec20e69df8.

* guix/scripts/environment.scm (create-environment): Check whether
SEPARATOR is #f.

build: Export register-root procedure.

* guix/scripts/build.scm: Export register-root procedure.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

Merge branch 'core-updates'

guix: Compress and decompress xz archives in parallel.

* guix/scripts/pack.scm (%compressors): Add flag '-T0' when calling "xz".
* guix/utils.scm (decompressed-port, compressed-port,
compressed-output-port): Same.

substitute: Send ‘User-Agent’ header.

* guix/scripts/substitute.scm (narinfo-request): Pass ‘User-Agent’ #:headers
to ‘build-request’.

Merge branch 'master' into core-updates

Most conflicts are from 6fd52309b8f52c9bb59fccffac53e029ce94b698.

import cran: Print package stream in the expected order.

* guix/scripts/import/cran.scm (guix-import-cran): Reverse list of packages.

Merge branch 'master' into core-updates

ui: Support Texinfo markup in package synopses.

* guix/ui.scm (package-field-string): New procedure.
(package-description-string): Use it.
(package-synopsis-string): New procedure.
(package->recutils): Use it.
* guix/scripts/lint.scm (check-synopsis-style)[check-texinfo-markup]:
New procedure.  Use it in checks.
* tests/lint.scm: Test it.
* gnu/packages/perl.scm (perl-try-tiny)[synopsis]: Adjust for the
Texinfo markup.

Merge remote-tracking branch 'origin/master' into core-updates

publish: Add '--nar-path'.

* guix/scripts/publish.scm (show-help, %options): Add '--nar-path'.
(%default-options): Add 'nar-path'.
(guix-publish): Honor it.

publish: Make the nar URL prefix a parameter.

* guix/scripts/publish.scm (narinfo-string): Add #:nar-path and honor it.
(render-narinfo): Likewise.
(make-request-handler): Likewise.
(run-publish-server): Likewise.
* tests/publish.scm ("custom nar path"): New test.

publish: Add '--public-key' and '--private-key'.

* guix/scripts/publish.scm (show-help, %options): Add --public-key and
--private-key.
* doc/guix.texi (Invoking guix publish): Document it.