* doc/guix.texi (Invoking guix pull): Add --url.

* guix/monads.scm: New file.
* tests/monads.scm: New file.
* Makefile.am (MODULES): Add guix/monads.scm.
  (SCM_TESTS): Add tests/monads.scm.
* doc/guix.texi (The Store Monad): New node.
  (The Store): Reference it.

* doc/guix.texi: Fix typos.

* doc/guix.texi (Invoking guix package): Mention that deleting
  generations prevents roll-back.
  (Invoking guix gc): Link to '--delete-generations'.

* guix/scripts/package.scm (matching-generations): Add
  'duration-relation' keyword parameter.
  (guix-package)[process-action](delete-generations): Pass
  #:duration-relation >.
* tests/guix-package.sh: Add test.
* doc/guix.texi (Invoking guix package): Clarify the meaning of
  durations for '--list-durations' and '--delete-durations'.

* guix/scripts/package.scm (switch-to-previous-generation): New function.
  (roll-back): Use the new function instead of 'switch-link'.
  (show-help): Add '--delete-generations'.
  (%options): Likewise.
  (guix-package)[process-actions]: Add 'current-generation-number',
  'display-and-delete', and 'delete-generation'.  Add support for
  '--delete-generations', and reindent the code.
* tests/guix-package.sh: Test '--delete-generations'.
* doc/guix.texi (Invoking guix-package): Document '--delete-generations'.

* guix/scripts/package.scm (guix-package)[process-query]: Change
  'list-generation' to not list the zeroth generation.
* tests/guix-package.sh: Test it.
* doc/guix.texi (Invoking guix package): Document it, and use the
  right term when talking about generations.

* doc/guix.texi (Invoking guix package): Move '--list-generations' below
  "In addition to these actions".

Suggested by Andreas Enge <andreas@enge.fr>.

* guix/scripts/package.scm (guix-package)[list-generations,
  list-installed]: Reverse the result of 'manifest-packages'.
* doc/guix.texi (Invoking guix package): Document the order of packages
  for '--list-generations' and '--list-installed'.

* guix/scripts/package.scm: Import (srfi srfi-19).
  (generation-time, matching-generations): New functions.
  (show-help): Add '--list-generations'.
  (%options): Likewise.
  (guix-package)[process-query]: Add support for '--list-generations'.
* guix/ui.scm: Import (srfi srfi-19) and (ice-9 regex).
  (string->generations, string->duration): New functions.
* tests/guix-package.sh: Test '--list-generations'.
* tests/ui.scm: Import (srfi srfi-19).
  Test 'string->generations' and 'string->duration'.
* doc/guix.texi (Invoking guix-package): Document '--list-generations'.

* guix/derivations.scm (derivation->output-path,
  derivation->output-paths): New procedures.
  (derivation-path->output-path): Use 'derivation->output-path'.
  (derivation-path->output-paths): Use 'derivation->output-paths'.
  (derivation): Accept 'derivation?' objects as inputs.  Return a single
  value.
  (build-derivations): New procedure.
  (compiled-modules): Use 'derivation->output-paths'.
  (build-expression->derivation)[source-path]: Add case for when the
  input matches 'derivation?'.
  [prologue]: Accept 'derivation?' objects in INPUTS.
  [mod-dir, go-dir]: Use 'derivation->output-path'.
* guix/download.scm (url-fetch): Adjust to the single-value return.
* guix/packages.scm (package-output): Use 'derivation->output-path'.
* guix/scripts/build.scm (guix-build): When the argument is
  'derivation-path?', pass it through 'read-derivation'.
  Use 'derivation-file-name' to print out the .drv file names, and to
  register them.  Use 'derivation->output-path' instead of
  'derivation-path->output-path'.
* guix/scripts/package.scm (roll-back): Adjust to the single-value
  return.
  (guix-package): Use 'derivation->output-path'.
* guix/ui.scm (show-what-to-build): Adjust to deal with 'derivation?'
  objects instead of .drv file names.
* gnu/system/grub.scm (grub-configuration-file): Use
  'derivation->output-path' instead of 'derivation-path->output-path'.
* gnu/system/vm.scm (qemu-image, system-qemu-image): Likewise.
* tests/builders.scm, tests/derivations.scm, tests/packages.scm,
  tests/store.scm, tests/union.scm: Adjust to the new calling
  convention.
* doc/guix.texi (Defining Packages, The Store, Derivations): Adjust
  accordingly.

* guix/store.scm (add-text-to-store): Make 'references' optional.
* tests/store.scm ("dead-paths", "references"): Use 'add-text-to-store'
  with no optional argument.
* doc/guix.texi (The Store): Adjust accordingly.

* doc/guix.texi: Add second copyright notice again inside @ifinfo, needed
  since the first one does not appear in the info output.
  Partially undoes commit da7cabd4.

* doc/guix.texi (Bootstrapping): Specify an image width for the TeX
  output.  Before that, the image would be much wider than the US Letter
  page width.

This undoes commit 575ed8d5 ("doc: Create own Makefile.am in subdirectory."),
and fixes a bug whereby "make pdf" or "make ps" wouldn't do anything.

* doc/Makefile.am: Remove.
* doc.am: New file.  Use `-local' rules to build the image.
* Makefile.am: Include it.
* configure.ac: Use `-Woverride' to avoid undesired overridding of
  Automake rules.

* doc/guix.texi: Three new subsections.

* doc/guix.texi: Drop duplicate copyright notice, start section
    "Packaging Guidelines" with existant text.

* doc/Makefile.am: New file.
* Makefile.am: Reference subdirectory doc.

* guix/derivations.scm (derivation, build-expression->derivation):
  Rename #:dependency-graphs to #:references-graphs, for consistency in
  the terminology.
* tests/derivations.scm: Adjust accordingly.

* guix/derivations.scm (build-expression->derivation): Add
  #:dependency-graphs keyword argument.  Pass it to `derivation'.
* tests/derivations.scm ("build-expression->derivation with
  #:dependency-graphs"): New test.
* doc/guix.texi (Derivations): Update `build-expression->derivation'
  description.

* guix/derivations.scm (derivation): Add `dependency-graphs' keyword
  parameter; honor it.
* tests/derivations.scm (bootstrap-binary): New procedure.
  (%bash): Use it.
  (%mkdir): New variable.
  (directory-contents): Add `slurp' optional parameter.
  ("derivation with #:dependency-graphs"): New test.
* doc/guix.texi (Derivations): Update accordingly.

* guix/derivations.scm (derivation): Turn `system', `env-vars', and
  `inputs' into keyword parameters.
  (build-expression->derivation): Adjust accordingly.
* gnu/packages/bootstrap.scm (%bootstrap-guile): Likewise.
* tests/derivations.scm, tests/store.scm: Likewise.
* doc/guix.texi (Derivations): Likewise.

* doc/guix.texi (Setting Up the Daemon): Document the default content of
  the chroot, and the /dev/shm caveat.

* doc/guix.texi (Adding New Packages): New section.
  (Packaging Guidelines): Make a subsection thereof.
  (From the Source Tarball to the Package): New subsection.
  (Contributing): Link to "Adding New Packages".
  (Package Modules): Link to modules in Guile's manual.

* doc/guix.texi (Requirements): Require Guile 2.0.5+.
* README: Ditto.

* doc/guix.texi (Contributing): Refer to guix-devel@gnu.org.

* doc/guix.texi (Installing Debugging Files): New node.
  (Packages with Multiple Outputs): Add cross-reference.

* doc/guix.texi (Packages with Multiple Outputs): New node.
  (Invoking guix package): Refer to it.

* HACKING (Packaging Guidelines): Remove.
* doc/guix.texi (Packaging Guidelines): New node.

* HACKING (Porting the Guix distro on a new platform): Remove.
* doc/guix.texi (Porting): New node.  Describe cross-compilation as the
  only approach.

* doc/guix.texi (Package Modules): New node, with material formerly
  under "GNU Distribution".
  (Bootstrapping): New node.
* Makefile.am (EXTRA_DIST): Add doc/images/bootstrap-graph.dot and
  doc/images/bootstrap-graph.eps.
  (infoimagedir, dist_infoimage_DATA, DOT_OPTIONS): New variable.
  (.dot.png, .dot.eps, doc/guix.pdf, doc/guix.info, doc/guix.ps): New
  targets.
* doc/images/bootstrap-graph.dot: New file.

* guix/scripts/gc.scm (show-help, %options): Add `--requisites'.
  (guix-gc): Handle it.
* doc/guix.texi (Invoking guix gc): Document `--requisites'.
* NEWS: Update.

* HACKING: Update the command names from `guix-build' to `guix build' & co.
  (Submitting Patches, Packaging Guidelines): New sections.
* doc/guix.texi (Contributing): New section.

* guix/scripts/build.scm (%options, show-help): Add `--fallback'.
  (guix-build): Call `set-build-options' with #:fallback?.
* guix/scripts/package.scm (%options, show-help): Add `--fallback'.
  (guix-package): Call `set-build-options' with #:fallback?.
* doc/guix.texi (Invoking guix package, Invoking guix build): Document
  `--fallback'.

* doc/guix.texi (Introduction, Requirements): Rephrase and fix typos.

* guix/scripts/build.scm (derivations-from-package-expressions): Add
  `package-derivation' parameter.
  (show-help, %options): Add `--target'.
  (guix-build): Use `package-cross-derivation' when `--target' is
  passed.
* tests/guix-build.sh: Add dry-run test with `--target'.
* doc/guix.texi (Invoking guix build): Document `--target'.

* guix/packages.scm (package-transitive-target-inputs,
  package-transitive-native-inputs): New procedures.
  (package-derivation): Parametrize `%current-target-system'.
  (package-cross-derivation): Implement.
* guix/utils.scm (%current-target-system): New variable.
* tests/packages.scm ("package-cross-derivation"): New test.
* doc/guix.texi (Defining Packages): Document
  `package-cross-derivation'.