Merge branch 'master' into core-updates

store: Add query-path-info operation.

* guix/store.scm (<path-info>): New record type.
  (read-path-info): New procedure.
  (read-arg): Add 'path-info' syntax.
  (query-path-info): New variable.
* tests/store.scm ("query-path-info"): New test.

Merge branch 'master' into core-updates

store: Default to a non-empty list of substituters.

Fixes <http://bugs.gnu.org/20163>.
Reported by Mark H Weaver <mhw@netris.org>.

* guix/store.scm (%default-substitute-urls): New variable.
  (set-build-options): Change default value of #:substitute-urls to
  %DEFAULT-SUBSTITUTE-URLS.

Merge branch 'master' into core-updates

store: Remove debugging leftover.

* guix/store.scm (set-build-options): Remove leftover 'pk' call from
  41c45e7.

store: Add preliminary support for client-supplied substitute URLs.

* guix/store.scm (set-build-options): Rename #:binary-caches to
  #:substitute-urls.  Actually pass it in 'pairs' under the
  "substitute-urls" key.
* guix/scripts/substitute-binary.scm (%cache-url): Add comment for
  "untrusted-substitute-urls".

store: Attempt to decode build logs as UTF-8.

* guix/serialization.scm (read-maybe-utf8-string): New procedure.
* guix/store.scm (process-stderr): Use it for the build log and errors.
* tests/store.scm ("current-build-output-port, UTF-8",
  "current-build-output-port, UTF-8 + garbage"): New tests.

Merge branch 'master' into core-updates

store: Add optional 'references' parameter to 'text-file'.

* guix/store.scm (text-file): Add optional 'references' parameter.  Pass
  it to 'add-text-to-store'.
* doc/guix.texi (The Store Monad): Adjust accordingly.

store: Remove 'build-derivations'.

* guix/store.scm (build-derivations): Remove.
* guix/derivations.scm (build-derivations): Write in terms of
  'build-things'.
* doc/guix.texi (Invoking guix build): Adjust text accordingly.

store: Add 'build-things'.

* guix/store.scm (operation-id): Rename 'build-derivations' to
  'build-things', as per Nix commit 1aba0bf0.
  (build-derivations): Rename to...
  (build-things): ... this.  Keep 'build-derivations' as an alias.
  (build): New procedure.
* tests/store.scm ("build-things with output path",
  "substitute + build-things with output path"): New tests.

store: Change 'run-with-store' to return a single value.

* guix/store.scm (run-with-store): Wrap 'run-with-state' in
  'call-with-values'.  Return only the first value.

store: Change 'store-lower' to preserve the original procedure's documentation.

* guix/store.scm (preserve-documentation): New procedure.
  (store-lift, store-lower): Use it.

store: Make '%store-monad' an alias for '%state-monad'.

* guix/store.scm (define-alias): New macro.
  (%store-monad, store-return, store-bind): Define as aliases of the
  corresponding %STATE-MONAD part.
  (store-lift, text-file, interned-file): Return STORE as a second
  value.
  (run-with-store): Use 'run-with-state'.
* guix/packages.scm (set-guile-for-build, package-file): Return STORE as
  a second value.
* guix/monads.scm: Remove part of the module commentary.

store: Remove unused variable.

* guix/store.scm (export-paths): Remove unused variable 's'.

store: Add #:recursive? parameter to 'export-paths'.

* guix/store.scm (export-paths): Add #:recursive? parameter and honor
  it.
* tests/store.scm ("export/import incomplete", "export/import
  recursive"): New tests.

store: Add 'store-lower'.

* guix/store.scm (store-lower): New procedure.
* tests/store.scm ("store-lower"): New test.

monads: Move '%store-monad' and related procedures where they belong.

This turns (guix monads) into a generic module for monads, and moves the
store monad and related monadic procedures in their corresponding
module.

* guix/monads.scm (store-return, store-bind, %store-monad, store-lift,
  text-file, interned-file, package-file, package->derivation,
  package->cross-derivation, origin->derivation, imported-modules,
  compiled, modules, built-derivations, run-with-store): Move to...
* guix/store.scm (store-return, store-bind, %store-monad, store-lift,
  text-file, interned-file): ... here.
  (%guile-for-build): New variable.
  (run-with-store): Moved from monads.scm.  Remove default value for
  #:guile-for-build.
* guix/packages.scm (default-guile): Export.
  (set-guile-for-build): New procedure.
  (package-file, package->derivation, package->cross-derivation,
  origin->derivation): Moved from monads.scm.
* guix/derivations.scm (%guile-for-build): Remove.
  (imported-modules): Rename to...
  (%imported-modules): ... this.
  (compiled-modules): Rename to...
  (%compiled-modules): ... this.
  (built-derivations, imported-modules, compiled-modules): New
  procedures.
* gnu/services/avahi.scm, gnu/services/base.scm, gnu/services/dbus.scm,
  gnu/services/dmd.scm, gnu/services/networking.scm,
  gnu/services/ssh.scm, gnu/services/xorg.scm, gnu/system/install.scm,
  gnu/system/linux-initrd.scm, gnu/system/shadow.scm, guix/download.scm,
  guix/gexp.scm, guix/git-download.scm, guix/profiles.scm,
  guix/svn-download.scm, tests/monads.scm: Adjust imports accordingly.
* guix/monad-repl.scm (default-guile-derivation): New procedure.
  (store-monad-language, run-in-store): Use it.
* build-aux/hydra/gnu-system.scm (qemu-jobs): Add explicit
  'set-guile-for-build' call.
* guix/scripts/archive.scm (derivation-from-expression): Likewise.
* guix/scripts/build.scm (options/resolve-packages): Likewise.
* guix/scripts/environment.scm (guix-environment): Likewise.
* guix/scripts/system.scm (guix-system): Likewise.
* doc/guix.texi (The Store Monad): Adjust module names accordingly.

Merge branch 'master' into 'core-updates'.