copy: Default to port 22.

Failing to do that, "%p" would be "0" when using "ProxyCommand"
in ~/.ssh/config.

* guix/scripts/copy.scm (send-to-remote-host): Default to port 22.
(retrieve-from-remote-host): Likewise.

guix system: Add "--file-system-type" option.

* guix/scripts/system.scm (process-action): Pass file-system-type to ...
(perform-action): ... here.  Add new keyword argument.  Pass new value to ...
(system-derivation-for-action): ... here.  Add new keyword argument.
Pass new value to system-disk-image.
* doc/guix.texi (disk-image): Document new option.

vm: Estimate the disk size by default.

* 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.

guix package: Allow '--rollback', after all.

* guix/scripts/package.scm (%options): Add "rollback" as an alias for
"roll-back".

guix package: 'guix package -r PKG -u' does not upgrade PKG.

Fixes <http://bugs.gnu.org/27262>.
Reported by Mark H Weaver <mhw@netris.org>.

* guix/scripts/package.scm (transaction-upgrade-entry): Check if ENTRY
matches 'manifest-transaction-removal-candidate?' and return TRANSACTION
if it does.
(process-actions): Move 'options->removable' from step 2 to step 1.

guix package: Warn about packages that no longer exist.

Fixes <http://bugs.gnu.org/27261>.
Reported by Mark H Weaver <mhw@netris.org>.

* guix/scripts/package.scm (transaction-upgrade-entry): Add call to
'warning' when NAME cannot be found in the package set.

refresh: Be more verbose when passed an explicit package list.

* guix/scripts/refresh.scm (check-for-package-update): Use
'version-compare' instead of 'version>?'.  When WARN? is true, print
something for the '=' and '<' cases.

environment: Disable profile collision checks.

Reported by Efraim Flashner.
This is a followup to a654dc4bcf7c8e205bdefa1a1d5f23444dd22778.

* guix/profiles.scm (profile-derivation): Add #:allow-collisions? and
honor it.
* guix/scripts/environment.scm (inputs->profile-derivation): Pass
 #:allow-collisions? #f to 'profile-derivation'.
* tests/guix-environment.sh: Test "guix environment guix".

guix package: '--search-paths' shows search paths from propagated inputs.

* guix/scripts/package.scm (process-query) <'search-paths>: Use
'manifest-transitive-entries' instead of 'manifest-entries'.

guix package: Always upgrade packages that have propagated inputs.

* guix/scripts/package.scm (transaction-upgrade-entry): Always upgrade
packages that have propagated inputs.

guix: Add texlive importer.

* guix/import/texlive.scm: New file.
* guix/scripts/import/texlive.scm: New file.
* Makefile.am (MODULES): Add them.
* tests/texlive.scm: New file.
* Makefile.am (SCM_TESTS): Add it.
* guix/scripts/import.scm (importers): Add texlive importer.
* doc/guix.texi (Invoking guix import): Document it.

guix package: '--search' sorts by relevance.

* guix/scripts/package.scm (find-packages-by-description): Rewrite to
compute a score based on the number of regexps matched and the number of
matches for each regexp.  Sort according to this score and return it as
a second value.
(process-query) <'search>: Capture the two return values of
'find-packages-by-description'.  Pass #:extra-fields to
'package->recutils'.
* doc/guix.texi (Invoking guix package): Mention relevance, give an
example.

derivations: Introduce 'read-derivation-from-file'.

This avoids the open/fstat/close syscalls upon a cache hit that we had
with the previous idiom:

  (call-with-input-file file read-derivation)

where caching happened in 'read-derivation' itself.

* guix/derivations.scm (%read-derivation): Rename to...
(read-derivation): ... this.
(read-derivation-from-file): New procedure.
(derivation-prerequisites, substitution-oracle)
(derivation-prerequisites-to-build):
(derivation-path->output-path, derivation-path->output-paths):
(derivation-path->base16-hash, map-derivation): Use
'read-derivation-from-file' instead of (call-with-input-file …
read-derivation).
* guix/grafts.scm (item->deriver): Likewise.
* guix/scripts/build.scm (log-url, options->things-to-build): Likewise.
* guix/scripts/graph.scm (file->derivation): Remove.
(derivation-dependencies, %derivation-node-type): Use
'read-derivation-from-file' instead.
* guix/scripts/offload.scm (guix-offload): Likewise.
* guix/scripts/perform-download.scm (guix-perform-download): Likewise.
* guix/scripts/publish.scm (load-derivation): Remove.
(narinfo-string): Use 'read-derivation-from-file'.

bootloader: Rename boot-name to bootloader-name.

* gnu/system (<boot-parameters>)[boot-name]: Rename field to...
[bootloader-name]: ... this.  Adjust users.
* gnu/scripts/system.scm: Adjust accordingly.

scripts: refresh: Add -m manifest option.

* guix/scripts/refresh.scm (%options): Add -m option,
(show-help): document it,
(packages-from-manifest): new procedure,
(guix-refresh): use packages from manifest if specified, otherwise
keep the previous behaviour.
* doc/guix.texi (Invoking guix refresh): document new option.

substitute: Do not display the installed size.

* guix/scripts/substitute.scm (process-substitution): Do not show the
installed size in the "Downloading" message.

syscalls: Provide 'free-disk-space'.

* guix/build/syscalls.scm (free-disk-space): New procedure.
* guix/scripts/gc.scm (guix-gc)[ensure-free-space]: Use it instead of
'statfs'.

Merge branch 'master' into staging

scripts: Set thread names.

This allows 'guix publish' threads as well as 'guix substitute' and
'guix offload' processes to be properly labeled in 'top', 'pstree', etc.

* guix/workers.scm (worker-thunk): Add #:thread-name parameter and honor it.
(make-pool): Likewise.
* guix/scripts/publish.scm (http-write): Add calls to 'set-thread-name'
in bodies of 'call-with-new-thread'.
(guix-publish): Call 'set-thread-name'.   Pass #:thread-name to 'make-pool'.
* guix/scripts/offload.scm (guix-offload): Call 'set-thread-name'.
* guix/scripts/substitute.scm (guix-substitute): Likewise.

Merge branch 'master' into staging