Fixes <https://bugs.gnu.org/27551>.
Reported by Leo Famulari <leo@famulari.name>.
This reinstates the following commits:
e3ddb1e83 * gnu: guile-cairo: Switch to Guile 2.2.
ae5c6ef39 * gnu: guile-gnome: Update to 2.16.5.
0fd8013fc * gnu: guile-rsvg: Update to commit 05c6a2fd.
66b9183c4 * gnu: guile-lib: Switch to Guile 2.2.
and adds the following changes:
* gnu/bootloader/grub.scm (svg->png): Add 'package->derivation' call for
GUILE-2.2. Pass #:guile-for-build to 'gexp->derivation'.
* gnu/build/svg.scm (svg->png): Add 'em' and 'ex' to the 'let-values'
form to account for all the values returned by
'rsvg-handle-get-dimensions', which Guile 2.2 does not truncate.
Fixes compilation by 'guix pull' where Guile-{RSVG,Cairo} are missing.
Reported by Efraim Flashner.
* gnu/build/svg.scm: Use 'module-autoload!' rather than 'module-use!'.
Based on a suggestion by Andy Wingo at
<https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00753.html>.
* gnu/build/svg.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.
* gnu/system/grub.scm (svg->png): Add #:width and #:height. Rewrite to
use (gnu build svg).
(resize-image): Remove.
(grub-background-image): Adjust accordingly.
