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
index 65079f9eb8..14818f84e0 100644
--- a/localedata/Makefile
+++ b/localedata/Makefile
@@ -169,7 +169,8 @@ endif
 # Files to install.
 install-others := $(addprefix $(inst_i18ndir)/, \
 			      $(addsuffix .gz, $(charmaps)) \
-			      $(locales))
+			      $(locales)) \
+                   $(inst_i18ndir)/SUPPORTED
 
 tests: $(objdir)/iconvdata/gconv-modules
 
@@ -380,6 +381,14 @@ endif
 
 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))
 guix/'>summary</a><a href='/guix/refs/?id=032f2e261caee641d29ebc604a7d7a9be2410ac7'>refs</a><a class='active' href='/guix/log/etc/guix-daemon.cil.in'>log</a><a href='/guix/tree/etc/guix-daemon.cil.in?id=032f2e261caee641d29ebc604a7d7a9be2410ac7'>tree</a><a href='/guix/commit/etc/guix-daemon.cil.in?id=032f2e261caee641d29ebc604a7d7a9be2410ac7'>commit</a><a href='/guix/diff/etc/guix-daemon.cil.in?id=032f2e261caee641d29ebc604a7d7a9be2410ac7'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/etc/guix-daemon.cil.in'>
<input type='hidden' name='id' value='032f2e261caee641d29ebc604a7d7a9be2410ac7'/><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=032f2e261caee641d29ebc604a7d7a9be2410ac7'>root</a>/<a href='/guix/log/etc?id=032f2e261caee641d29ebc604a7d7a9be2410ac7'>etc</a>/<a href='/guix/log/etc/guix-daemon.cil.in?id=032f2e261caee641d29ebc604a7d7a9be2410ac7'>guix-daemon.cil.in</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/etc/guix-daemon.cil.in?id=032f2e261caee641d29ebc604a7d7a9be2410ac7&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-01-26 09:31:45 +0100'>2022-01-26</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=bbc2fb0d52128c85c92251ed36d8063b3dcf3c3a'>etc: Remove redundant SELinux permissions block.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2022-01-24 11:28:14 +0100'>2022-01-24</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=98e74d520a30d1ed7d7b47d4f1d9afadefc699e3'>etc: Add more SELinux permissions for the daemon.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2021-05-22 19:53:17 +0200'>2021-05-22</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=35bd94a49257bbadcb3ca25342e5c1ec33f438f0'>etc: Add more SELinux permissions for the daemon.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-12-10 23:48:42 +0100'>2020-12-10</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=d677f3d6231d352fdb65b70f67d85fb5744e912c'>etc: Add more SELinux permissions for the daemon.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-11-27 21:33:59 +0100'>2020-11-27</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=1807632393d0723f3085c457517965c32715717a'>etc: Add more SELinux permissions for the daemon.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-11-26 00:31:47 +0100'>2020-11-26</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=402ebffe195890c9826cfa7519034dd12a48ae6a'>etc: Add more SELinux permissions for the daemon.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-11-25 23:24:52 +0100'>2020-11-25</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=d64e0261d0007413a795c4cf01f9d06b170da3f5'>etc: Add more SELinux permissions for the daemon.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-11-15 16:08:47 +0100'>2020-11-15</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=62343288ef6dc56027d268ef773ae699a4bbb76d'>etc: Updates for the guix-daemon SELinux policy.</a><span class='msg-avail'>...</span></td><td>Daniel Brooks</td></tr>