This patch allows us to use glibc's build system to build locales
in a package separate from glibc.

  1. Use 'localedef' from $PATH since we are not rebuilding it.
  2. Use '--no-archive' to avoid building the big locale archive, and
     because the already-built 'localedef' would want to write it
     to '/run/current-system/locale', which is not possible.
  3. Pass $(inst_complocaledir)/$$locale to install files in the right
     place, and because otherwise, 'localedef' fails with:
     "cannot write output files to `(null)'".

diff -ru glibc-2.29-old/localedata/Makefile glibc-2.29-new/localedata/Makefile
--- glibc-2.29-old/localedata/Makefile	2019-01-31 11:45:36.000000000 -0500
+++ glibc-2.29-new/localedata/Makefile	2019-07-03 22:48:35.662015071 -0400
@@ -385,7 +385,7 @@
 
 # Sometimes the whole collection of locale files should be installed.
 LOCALEDEF=I18NPATH=. GCONV_PATH=$(common-objpfx)iconvdata LC_ALL=C \
-$(rtld-prefix) $(common-objpfx)locale/localedef
+  localedef --no-archive
 install-locales: install-locale-archive
 
 # Create and install the locale-archive file.
@@ -414,7 +414,7 @@
 	input=`echo $$locale | sed 's/\([^.]*\)[^@]*\(.*\)/\1\2/'`; \
 	$(LOCALEDEF) $$flags --alias-file=../intl/locale.alias \
 		     -i locales/$$input -f charmaps/$$charset \
-		     $(addprefix --prefix=,$(install_root)) $$locale \
+		     $(addprefix --prefix=,$(install_root)) $(inst_complocaledir)/$$locale \
 	&& echo ' done';
 endef
 
x/diff/gnu/packages/mtools.scm?id=589c99e6f6ef17f30c541042768557a72706df47'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/mtools.scm'>
<input type='hidden' name='id' value='589c99e6f6ef17f30c541042768557a72706df47'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=589c99e6f6ef17f30c541042768557a72706df47'>root</a>/<a href='/guix/log/gnu?id=589c99e6f6ef17f30c541042768557a72706df47'>gnu</a>/<a href='/guix/log/gnu/packages?id=589c99e6f6ef17f30c541042768557a72706df47'>packages</a>/<a href='/guix/log/gnu/packages/mtools.scm?id=589c99e6f6ef17f30c541042768557a72706df47'>mtools.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/packages/mtools.scm?id=589c99e6f6ef17f30c541042768557a72706df47&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-01-16 01:00:00 +0100'>2022-01-16</span></td><td><a href='/guix/commit/gnu/packages/mtools.scm?id=5adec4cc0582c2bd0c13a05a52094a07bd2aea13'>gnu: mtools: Update to 4.0.37.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/mtools.scm (mtools): Update to 4.0.37.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2021-12-18 17:35:47 +0100'>2021-12-18</span></td><td><a href='/guix/commit/gnu/packages/mtools.scm?id=1eee548892676fd63052e0f3588f8dc8ab8f400b'>gnu: mtools: Update to 4.0.36.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/mtools.scm (mtools): Update to 4.0.36.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2021-09-03 23:26:18 +0200'>2021-09-03</span></td><td><a href='/guix/commit/gnu/packages/mtools.scm?id=1b0a9985787d02294f0a93c6b2c7e4abdb8e68c1'>gnu: mtools: Update to 4.0.35.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/mtools.scm (mtools): Update to 4.0.35.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2021-06-25 18:42:49 +0200'>2021-06-25</span></td><td><a href='/guix/commit/gnu/packages/mtools.scm?id=f378f1d05fb9a5ec5502147c360cf4cf0c7cff7d'>gnu: exfat-utils: Move to (gnu packages file-systems).</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/mtools.scm (exfat-utils): Move from here…
* gnu/packages/file-systems.scm (exfat-utils): …to here.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2021-06-25 13:27:11 +0200'>2021-06-25</span></td><td><a href='/guix/commit/gnu/packages/mtools.scm?id=00a2c666dc217c82867bc494a2054d3a2fb321f4'>gnu: mtools: Update to 4.0.31.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/mtools.scm (mtools): Update to 4.0.31.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2021-06-03 18:23:38 +0200'>2021-06-03</span></td><td><a href='/guix/commit/gnu/packages/mtools.scm?id=606b200fe7448b85de5f4ed9d4aa7677b227a980'>gnu: mtools: Update to 4.0.29.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/mtools.scm (mtools): Update to 4.0.29.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>