search-paths: Add 'evaluate-search-paths', from (guix scripts package).

* guix/scripts/package.scm (with-null-error-port,
  evaluate-search-paths): Move to...
* guix/search-paths.scm: ... here.
* guix/utils.scm (string-tokenize*): Move to...
* guix/search-paths.scm: ... here.
* tests/utils.scm ("string-tokenize*"): Adjust accordingly.

Move search path specifications to (guix search-paths).

* guix/packages.scm (<search-path-specification>,
  search-path-specification->sexp, sexp->search-path-specification):
  Move to...
* guix/search-paths.scm: ... here.  New file.
* Makefile.am (MODULES): Add it.
* guix/build-system/cmake.scm, guix/build-system/glib-or-gtk.scm,
  guix/build-system/gnu.scm, guix/build-system/haskell.scm,
  guix/build-system/perl.scm, guix/build-system/python.scm,
  guix/build-system/ruby.scm, guix/build-system/waf.scm,
  guix/profiles.scm, guix/scripts/package.scm: Use it.

substitute: Increase TTL from 24h to 36h.

* guix/scripts/substitute.scm (%narinfo-ttl): Increase to 36h.

guix: build: Fix indentation for --sources in help output.

* guix/scripts/build.scm (show-help)[--sources]: Make indentation
  consistent with other long options.

guix package: Introduce 'evaluate-search-paths'.

* guix/scripts/package.scm (evaluate-search-paths): New procedure, with
  most of the code formerly in 'search-path-environment-variables'.
  (search-path-environment-variables): Use it.

guix package: Move profile cleaning out of 'search-path-environment-variables'.

* guix/scripts/package.scm (user-friendly-profile): New procedure.
  (search-path-environment-variables): Remove 'profile' local variable.
  (display-search-paths): Explicitly call 'user-friendly-profile' for
  the argument to 'search-path-environment-variables'.
  (guix-package)[process-query]: Likewise.

guix: build: Add transitive source building.

* guix/scripts/build.scm (%options, options->derivations): Add --sources
  option.
* doc/guix.texi (Invoking guix build): Document --sources option.
* tests/guix-build.sh: Add tests.

profiles: Store search paths in manifests.

Discussed in <http://bugs.gnu.org/20255>.

* guix/packages.scm (sexp->search-path-specification): New variable.
* guix/profiles.scm (<manifest-entry>)[search-paths]: New field.
  (package->manifest-entry): Initialize it.
  (manifest->gexp): Match it.  Wrap #$deps in (propagated-inputs ...).
  Emit (search-paths ...).  Increment version.
  (find-package): New procedure.
  (sexp->manifest)[infer-search-paths]: New procedure.
  Use it to initialize the 'search-paths' field for versions 0 and 1.
  Add case for version 2.
* guix/scripts/package.scm (search-path-environment-variables)[manifest-entry->package]:
  Remove.
  Use 'manifest-entry-search-paths' instead of 'manifest-entry->package'
  plus 'package-native-search-paths'.
* tests/profiles.scm ("profile-manifest, search-paths"): New test.

Merge branch 'master' into core-updates

substitute: Fix file descriptor leak in 'http-multiple-get'.

In practice we would not leak much since we reconnect after ~100
requests (with nginx running on hydra.gnu.org.)

* guix/scripts/substitute.scm (http-multiple-get): Call 'close-port'
  before 'connect'.

guix package: Fix 'readlink*' implementation.

* guix/scripts/package.scm (readlink*): Fix to handle symlinks with
  relative targets.  Taken from ld-wrapper2.in.

guix package: -A and -s take supported systems into account.

* guix/scripts/package.scm (guix-package)[process-query]
  <list-available>: Restrict results to packages matching
  'supported-package?".
* guix/ui.scm (package->recutils): Print "systems:".
* tests/guix-package.sh: Add tests.
* doc/guix.texi (Invoking guix package): Adjust description of
  '--list-available' accordingly.

Merge branch 'core-updates'

Merge branch 'master' into core-updates

Conflicts:
	gnu-system.am
	gnu/packages/gstreamer.scm

refresh: Allow users to refer to specific package versions.

* guix/scripts/refresh.scm (guix-refresh): Use 'specification->package'
  instead of 'find-packages-by-name'.  This allows users to specify
  things like "qt-4.8.6".
* doc/guix.texi (Invoking guix refresh): Add an example.

profiles: Generalize "hooks" for 'profile-derivation'.

* guix/profiles.scm (info-dir-file): Remove (null? (manifest-entries
  manifest)) test.
  (ca-certificate-bundle): Likewise.
  (ghc-package-cache-file): Turn 'if' into 'and', and remove second
  arm.
  (%default-profile-hooks): New variable.
  (profile-derivation): Remove #:info-dir?, #:ghc-package-cache?, and
  #:ca-certificate-bundle?.  Add #:hooks.  Iterate over HOOKS.  Adjust
  'inputs' accordingly.
* guix/scripts/package.scm (guix-package): Adjust 'profile-derivation'
  call accordingly.
* tests/packages.scm ("--search-paths with pattern"): Likewise.
* tests/profiles.scm ("profile-derivation",
  "profile-derivation, inputs"): Likewise.

guix package: Add '--do-not-upgrade' option.

* guix/scripts/package.scm (%options): Add the '--do-not-upgrade' option.
  (show-help): Document it.
  (options->installable): Add 'do-not-upgrade-regexps' variable.
  Use it in 'packages-to-upgrade'.
* doc/guix.texi (Invoking guix package): Document the '--do-not-upgrade'
  option.

lint: Add a 'derivation' checker.

* guix/scripts/lint.scm (check-derivation): New procedure.
  (%checkers): Add 'derivation' checker.
* tests/lint.scm ("derivation: invalid arguments"): New test.

lint: Report patches that cannot be found.

* guix/scripts/lint.scm (check-patch-file-names): Wrap body in 'guard'.
* tests/lint.scm ("patches: not found"): New test.

lint: Rename 'check-patches' to 'check-patch-file-names'.

* guix/scripts/lint.scm (check-patches): Rename to...
  (check-patch-file-names): ... this.  Rename 'filename' to 'file'.
  (%checkers): Adjust accordingly.
* tests/lint.scm ("patches: file names"): Likewise.