This patch is taken from debian's glibc package (generate-supported.mk).
It install the localedata/SUPPORTED file of the glibc. This file lists
all the supported locales of the glibc.

diff --git a/localedata/Makefile b/localedata/Makefile
--- a/localedata/Makefile
+++ b/localedata/Makefile
@@ -176,7 +176,8 @@
 else
 install-others := $(addprefix $(inst_i18ndir)/, \
 			      $(addsuffix .gz, $(charmaps)) \
-			      $(locales))
+			      $(locales)) \
+                   $(inst_i18ndir)/SUPPORTED
 endif
 
 tests: $(objdir)/iconvdata/gconv-modules
@@ -401,6 +402,14 @@
 
 include SUPPORTED
 
+$(inst_i18ndir)/SUPPORTED: SUPPORTED $(+force)
+	for locale in $(SUPPORTED-LOCALES); do \
+		[ $$locale = true ] && continue; \
+		echo $$locale | sed 's,/, ,' >> LOCALES; \
+	done
+	$(make-target-directory)
+	$(INSTALL_DATA) LOCALES $@
+
 INSTALL-SUPPORTED-LOCALE-ARCHIVE=$(addprefix install-archive-, $(SUPPORTED-LOCALES))
 INSTALL-SUPPORTED-LOCALE-FILES=$(addprefix install-files-, $(SUPPORTED-LOCALES))
 
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<tr><td><span title='2022-09-22 16:00:29 +0200'>2022-09-22</span></td><td><a href='/guix/commit/gnu/installer/user.scm?id=4814ec284f8a2870e6457c05f414ad31df4e3f57'>installer: Move &lt;secret&gt; to utils and use it for crypt passwords.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/installer/user.scm (&lt;secret&gt;, secret?, make-secret, secret-content): Move
to utils.scm.
* gnu/installer/utils.scm (&lt;secret&gt;, secret?, make-secret, secret-content):
Moved from user.scm.
* gnu/installer/newt/partition.scm (prompt-luks-passwords): Make password a
&lt;secret&gt;.
* gnu/installer/parted.scm (luks-format-and-open): Unwrap secret.

Signed-off-by: Mathieu Othacehe &lt;othacehe@gnu.org&gt;
</span></span></td><td>Josselin Poiret</td></tr>
<tr><td><span title='2022-08-08 11:54:25 +0200'>2022-08-08</span></td><td><a href='/guix/commit/gnu/installer/user.scm?id=ff9522fb69b9f4a31a5b766029e26dc53a2d1cf8'>installer: Add comments and vertical space to the generated config.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/installer/parted.scm (user-partitions-&gt;configuration): Introduce
vertical space and a comment.
* gnu/installer/services.scm (G_): New macro.
(%system-services): Add comment for OpenSSH.
(system-services-&gt;configuration): Add vertical space and comments.
* gnu/installer/user.scm (users-&gt;configuration): Add comment.
* gnu/installer/steps.scm (format-configuration): Add comment.
(configuration-&gt;file): Expound leading comment.  Pass #:format-comment
to 'pretty-print-with-comments/splice'.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-05-21 00:15:08 +0200'>2022-05-21</span></td><td><a href='/guix/commit/gnu/installer/user.scm?id=48c748226e2a94d2dec9bfdf84601455f00d6f5e'>Revert "installer: user: Remove useless filtering."</a><span class='msg-avail'>...<span class='msg-tooltip'>This reverts commit c2125e59d0774cda3e559adeb056459a5f23586b.

Fixes &lt;https://issues.guix.gnu.org/55361&gt;.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-04-06 21:19:08 +0200'>2022-04-06</span></td><td><a href='/guix/commit/gnu/installer/user.scm?id=c2125e59d0774cda3e559adeb056459a5f23586b'>installer: user: Remove useless filtering.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/installer/user.scm (users-&gt;configuration): Remove root account filtering
that is now performed in the "run-user-add-page" procedure.
</span></span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2022-02-02 16:46:44 +0100'>2022-02-02</span></td><td><a href='/guix/commit/gnu/installer/user.scm?id=112ef30b84744872b3a7617d9e54b3df5db95560'>installer: Turn passwords into opaque records.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/installer/user.scm (&lt;secret&gt;, secret?, make-secret,
secret-content): Add opaque &lt;secret&gt; record that boxes its contents,
with a custom printer that doesn't display anything.
* gnu/installer/newt/user.scm (run-user-add-page, run-user-page): Box
it.
* gnu/installer/final.scm (create-user-database): Unbox it.

Signed-off-by: Mathieu Othacehe &lt;othacehe@gnu.org&gt;
</span></span></td><td>Josselin Poiret</td></tr>