Partly fixes <https://bugs.gnu.org/44760>.
* guix/build/store-copy.scm (copy-store-item): New procedure.
(populate-store): Use it instead of the inline 'copy-recursively' call.
* guix/scripts/system.scm (copy-item): Likewise.
Pass #:reset-timestamps? and #:deduplicate? to 'register-path'.
Until now deduplication was performed as an additional pass after
copying files, which involve re-traversing all the files that had just
been copied.
* guix/store/deduplication.scm (copy-file/deduplicate): New procedure.
* tests/store-deduplication.scm ("copy-file/deduplicate"): New test.
* guix/build/store-copy.scm (populate-store): Add #:deduplicate?
parameter and honor it.
* tests/gexp.scm ("gexp->derivation, store copy"): Pass #:deduplicate? #f
to 'populate-store'.
* gnu/build/image.scm (initialize-root-partition): Pass #:deduplicate?
to 'populate-store'. Pass #:deduplicate? #f to 'register-closure'.
* gnu/build/vm.scm (root-partition-initializer): Likewise.
* gnu/build/install.scm (populate-single-profile-directory): Pass
#:deduplicate? #f to 'populate-store'.
* gnu/build/linux-initrd.scm (build-initrd): Likewise.
* guix/scripts/pack.scm (self-contained-tarball)[import-module?]: New
procedure.
[build]: Pass it as an argument to 'source-module-closure'.
* guix/scripts/pack.scm (squashfs-image)[build]: Wrap in
'with-extensions'.
* gnu/system/linux-initrd.scm (expression->initrd)[import-module?]: New
procedure.
[builder]: Pass it to 'source-module-closure'.
* gnu/system/install.scm (cow-store-service-type)[import-module?]: New
procedure. Pass it to 'source-module-closure'.
Until now, 'populate-store' would reset permissions but not timestamps,
so callers would resort to going through an extra directory traversal to
reset timestamps.
* guix/build/store-copy.scm (reset-permissions): Remove.
(copy-recursively): New procedure.
(populate-store): Pass #:keep-permissions? to 'copy-recursively'.
Remove call to 'reset-permissions'.
* tests/gexp.scm ("gexp->derivation, store copy"): In BUILD-DRV, check
whether 'populate-store' canonicalizes permissions and timestamps.
* gnu/build/image.scm (initialize-root-partition): Pass #:reset-timestamps? #f
to 'register-closure'.
* gnu/build/vm.scm (root-partition-initializer): Likewise.
Fixes a bug whereby directories in the output of 'guix pack -f tarball'
would not be read-only.
* guix/build/store-copy.scm (reset-permissions): New procedure.
(populate-store): Pass #:keep-mtime? #t to 'copy-recursively'. Call
'reset-permissions'.
* tests/pack.scm ("self-contained-tarball"): In CHECK, define
'canonical?' and use it to check that every file has an mtime of 1 and
is read-only.
* tests/guix-pack.sh: Invoke "chmod -Rf +w" before "rm -rf" in trap.
* guix/build/store-copy.scm (store-info): Export.
* guix/store/database.scm (register-items): New procedure.
(register-path): Implement in terms of 'register-items'.
* gnu/build/install.scm (register-closure): Use 'register-items' instead
of 'for-each' and 'register-path'.
The previous implementation of 'read-reference-graph' was good enough
for many use cases, but it discarded the graph structure, which is
useful information in some cases.
* guix/build/store-copy.scm (<store-info>): New record type.
(read-reference-graph): Rewrite to return a list of <store-info>.
(closure-size, populate-store): Adjust accordingly.
* gnu/services/base.scm (references-file): Adjust accordingly.
* gnu/system/vm.scm (system-docker-image): Likewise.
* guix/scripts/pack.scm (squashfs-image, docker-image): Likewise.
* tests/gexp.scm ("gexp->derivation #:references-graphs"): Likewise.
* gnu/build/vm.scm (estimated-partition-size): New procedure.
* gnu/system/vm.scm (expression->derivation-in-linux-vm):
Change #:disk-image-size default to 'guess.
[builder]: When DISK-IMAGE-SIZE is 'guess, use
'estimated-partition-size' and compute and estimate of the image size.
(qemu-image): Likewise.
* guix/build/store-copy.scm (file-size, closure-size): New procedures.
* guix/scripts/system.scm (%default-options): Change 'image-size' to
'guess.
* doc/guix.texi (Building the Installation Image): Remove '--image-size'
flag from example.
(Invoking guix system): Document the image size estimate.
