* gnu/packages.scm (fold2): Remove.
* guix/utils.scm (fold2): New procedure. Generalization of the above to
one and two lists.
* tests/utils.scm ("fold2, 1 list", "fold2, 2 lists"): New tests.
* gnu/packages.scm (find-newest-available-packages):
New exported procedure.
* guix-build.in (newest-available-packages, find-best-packages-by-name):
New procedures.
(find-package): Use find-best-packages-by-name, to guarantee that
if a version number is not specified, only the newest versions will
be considered.
* guix-package.in (%options): Add --upgrade/-u option.
(newest-available-packages, find-best-packages-by-name, upgradeable?):
New procedures.
(find-package): Use find-best-packages-by-name, to guarantee that
if a version number is not specified, only the newest versions will
be considered.
(process-actions): Implement upgrade option.
* doc/guix.texi (Invoking guix-package): In the description of --install,
mention that if no version number is specified, the newest available
version will be selected.
Ludovic Courtès