This avoids starting derivation builds just for the sake of knowing the
references of their outputs, thereby restoring the expected behavior of
--dry-run when substitutes are available.
* guix/grafts.scm (non-self-references): Remove 'store' parameter, and
add 'references'. Use it. Update caller.
(references-oracle): New variable.
(cumulative-grafts): Add 'references' parameter and use it. Update
callers.
(graft-derivation): Remove 'build-derivations' call. Add call to
'references-oracle'.
Fixes <http://bugs.gnu.org/22139>.
* guix/grafts.scm (graft-derivation): Rename to...
(graft-derivation/shallow): ... this.
(graft-origin-file-name, item->deriver, non-self-references)
(cumulative-grafts, graft-derivation): New procedures
* tests/grafts.scm ("graft-derivation, grafted item is a direct
dependency"): Clarify title. Use 'grafted' instead of 'graft' to refer
to the grafted derivation.
("graft-derivation, grafted item is an indirect dependency")
("graft-derivation, no dependencies on grafted output"): New tests.
* guix/packages.scm (input-graft): Change to take a package instead of
an input.
(input-cross-graft): Likewise.
(fold-bag-dependencies): New procedure.
(bag-grafts): Rewrite in terms of 'fold-bag-dependencies'.
* tests/packages.scm ("package-derivation, indirect grafts"): Comment out.
* doc/guix.texi (Security Updates): Mention run-time dependencies and
recursive grafting.
Before that, outputs of a derivation could be left referring to the
ungrafted version of the derivation.
* guix/grafts.scm (graft-derivation)[outputs]: Change to a list of
name/file pairs.
* guix/grafts.scm (graft-derivation)[build]: Add 'old-outputs' variable
and use it when computing 'mapping'. Use 'mapping' directly.
* tests/grafts.scm ("graft-derivation, multiple outputs"): New test.
