environment: Correct typo.

* guix/scripts/environment.scm (create-environment): Fix typo.

gnu: capnproto: Update to 0.6.0.

* gnu/packages/serialization.scm (capnproto): Update to 0.6.0.

gnu: libmpack: Update to 1.0.5.

* gnu/packages/serialization.scm (libmpack): Update to 1.0.5.

gnu: msgpack: Update to 1.4.2.

* gnu/packages/serialization.scm (msgpack): Update to 1.4.2.

gnu: dmenu: Update to 4.7.

* gnu/packages/suckless.scm (dmenu): Update to 4.7.

gnu: bind: Update to 9.11.1.

* gnu/packages/dns.scm (bind): Update to 9.11.1.
[license]: Change isc to mpl2.0.

Signed-off-by: Leo Famulari <leo@famulari.name>

doc: Add 'Debugging Build Failures' node.

* doc/guix.texi (Debugging Build Failures): New node.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

refresh: Use (guix discovery).

* guix/scripts/refresh.scm (maybe-updater, list-updaters): Remove.
(importer-modules): New procedure.
(%updaters): Define using 'fold-module-public-variables'.  Turn into a
promise and adjust users.

Add (guix discovery).

* guix/discovery.scm, tests/discovery.scm: New files.
* gnu/packages.scm (scheme-files, file-name->module-name)
(scheme-modules, all-package-modules): Remove.
(fold-packages): Rewrite in terms of 'fold-module-public-variables'.
* gnu/tests.scm: Use (guix discovery).
* Makefile.am (MODULES): Add guix/discovery.scm.
(SCM_TESTS): Add tests/discovery.scm.

gnu: Add fish-guix.

* gnu/packages/shells.scm (fish-guix): New variable.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu: Add missing copyright line.

* gnu/packages/version-control.scm: Add missing copyright line for commit
db88b5a.

gnu: gitolite: Avoid references to the store in authorized_keys.

* gnu/packages/version-control.scm (gitolite)[arguments]: Substitute
'$glshell' with 'gitolite-shell' in ssh-authkeys.

gnu: Add emacs-gnuplot.

* gnu/packages/emacs.scm (emacs-gnuplot): New variable.

gnu: Add gfortran@7.

* gnu/packages/gcc.scm (gfortran@7): New variable.

gnu: libressl: Update to 2.5.4.

* gnu/packages/tls.scm (libressl): Update to 2.5.4.
[home-page]: Use https.

gnu: tlp: Install all files.

* gnu/packages/linux.scm (tlp)[arguments]: Add ‘fix-installation’ phase so
the installation no longer aborts half-way, and use ‘zero?’ in the install
phase so this cannot go undetected again.

ui: Rename '_' to 'G_'.

This avoids collisions with '_' when the latter is used as a 'match'
pattern for instance.  See
<https://lists.gnu.org/archive/html/guix-devel/2017-04/msg00464.html>.

* guix/ui.scm: Rename '_' to 'G_'.
* po/guix/Makevars (XGETTEXT_OPTIONS): Adjust accordingly.
* build-aux/compile-all.scm (warnings): Remove 'format'.
* gnu/packages.scm,
gnu/services.scm,
gnu/services/shepherd.scm,
gnu/system.scm,
gnu/system/shadow.scm,
guix/gnupg.scm,
guix/http-client.scm,
guix/import/cpan.scm,
guix/import/elpa.scm,
guix/import/pypi.scm,
guix/nar.scm,
guix/scripts.scm,
guix/scripts/archive.scm,
guix/scripts/authenticate.scm,
guix/scripts/build.scm,
guix/scripts/challenge.scm,
guix/scripts/container.scm,
guix/scripts/container/exec.scm,
guix/scripts/copy.scm,
guix/scripts/download.scm,
guix/scripts/edit.scm,
guix/scripts/environment.scm,
guix/scripts/gc.scm,
guix/scripts/graph.scm,
guix/scripts/hash.scm,
guix/scripts/import.scm,
guix/scripts/import/cpan.scm,
guix/scripts/import/cran.scm,
guix/scripts/import/crate.scm,
guix/scripts/import/elpa.scm,
guix/scripts/import/gem.scm,
guix/scripts/import/gnu.scm,
guix/scripts/import/hackage.scm,
guix/scripts/import/nix.scm,
guix/scripts/import/pypi.scm,
guix/scripts/import/stackage.scm,
guix/scripts/lint.scm,
guix/scripts/offload.scm,
guix/scripts/pack.scm,
guix/scripts/package.scm,
guix/scripts/perform-download.scm,
guix/scripts/publish.scm,
guix/scripts/pull.scm,
guix/scripts/refresh.scm,
guix/scripts/size.scm,
guix/scripts/substitute.scm,
guix/scripts/system.scm,
guix/ssh.scm,
guix/upstream.scm: Use 'G_' instead of '_'.  Most of this change was
obtained by running: "sed -i -e's/(_ "/(G_ "/g' `find -name \*.scm`".

gnu: Add mes.

* gnu/packages/mes.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu: Add gcc@7.

* gnu/packages/gcc.scm (gcc@7): New variable.

gnu: connman: Update to 1.34.

* gnu/packages/connman.scm (connman): Update to 1.34.