self: Use a 'guile' that doesn't complain about locales.

Since commit ba48895899a117d6ace2209c3f54411a4a989133, selected UTF-8
locales are bundled.  However, because 'guix-command' is itself a Guile
script, users would still see Guile's warning, particularly on foreign
distros:

  $ LC_ALL=sdf guix foo
  guile: warning: failed to install locale
  hint: Consider installing the `glibc-utf8-locales' [...]

User commands would print that warning, but more importantly, each
invocation of 'guix substitute' would print it, even though
'guix-daemon.service' explicitly chooses "en_US.utf8", which is in
'glibc-utf8-locales'.  This leads to confusion since users would keep
seeing this message unless/until they realize they also need to install
'glibc-utf8-locales' in root's profile.

This patch gets rid of "guile: warning: ..." for a guix-pulled 'guix'
command.

* guix/self.scm (specification->package): Add "gcc-toolchain".
(quiet-guile): New procedure.
(guix-command): Use it.
* gnu/packages/aux-files/guile-launcher.c: New file.
* Makefile.am (AUX_FILES): Add it.

1 files changed, 46 insertions, 0 deletions

diff --git a/gnu/packages/aux-files/guile-launcher.c b/gnu/packages/aux-files/guile-launcher.c
new file mode 100644
index 0000000000..886ede2846
--- /dev/null
+++ b/gnu/packages/aux-files/guile-launcher.c
@@ -0,0 +1,46 @@
+/* GNU Guix --- Functional package management for GNU
+   Copyright 1996-1997,2000-2001,2006,2008,2011,2013,2018
+      Free Software Foundation, Inc.
+   Copyright (C) 2020 Ludovic Courtès <ludo@gnu.org>
+
+   This file is part of GNU Guix.
+
+   GNU Guix is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or (at
+   your option) any later version.
+
+   GNU Guix is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* This file implements a variant of the 'guile' executable that does not
+   complain about locale issues.  */
+
+#include <locale.h>
+#include <libguile.h>
+
+static void
+inner_main (void *unused, int argc, char **argv)
+{
+  scm_shell (argc, argv);
+}
+
+int
+main (int argc, char **argv)
+{
+  /* Try to install the current locale; remain silent if it fails.  */
+  if (setlocale (LC_ALL, "") == NULL)
+    /* The 'guix pull'-provided 'guix' includes at least en_US.utf8 so use
+       that.  That gives us UTF-8 support for 'scm_to_locale_string', etc.,
+       which is always preferable over the C locale.  */
+    setlocale (LC_ALL, "en_US.utf8");
+
+  scm_install_gmp_memory_functions = 1;
+  scm_boot_guile (argc, argv, inner_main, 0);
+  return 0; /* never reached */
+}