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='2020-07-29 13:07:25 +0200'>2020-07-29</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=f6ea0815ebe2964c5fd0b807bd17c0727e88cbfa'>gnu: Update LXDE home page.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-07-12 23:08:15 +0200'>2020-07-12</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=b0e7b6992f3f845e83cfbca4d700b51dba50b4d5'>gnu: Remove ".git" from "https://github/…/….git".</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-06-26 22:11:05 +0200'>2020-06-26</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=e6685186a5bbd5fecde4b4daa9d60eee35d2c783'>gnu: lxrandr: Depend on xrandr.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-05-26 00:19:40 +0200'>2020-05-26</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=4fa75903fc4146e3f2c94ba7bb1304229c2d413a'>gnu: lxrandr: Don't use NAME in source URI.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-05-26 00:19:40 +0200'>2020-05-26</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=85343f4978cf68c5239f72fd81b30f6bb1e5ea0e'>gnu: lxrandr: Update to 0.3.2.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-05-26 00:19:40 +0200'>2020-05-26</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=4f3e8733f90a8ec943a4b387a27e4002cdd2f324'>gnu: lxpanel: Don't use NAME in source URI.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-05-26 00:19:40 +0200'>2020-05-26</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=46b02378f07250caa09a3bc690014724956e1a4c'>gnu: lxpanel: Update to 0.10.0.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-05-26 00:19:40 +0200'>2020-05-26</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=00c63b8d9dd264b930deeb496713ebce7d2bace2'>gnu: lxsession: Don't use NAME in source URI.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-05-26 00:19:40 +0200'>2020-05-26</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=53bd021f1b3ff78150e75af28b13b2da08af6d36'>gnu: lxsession: Update to 0.5.5.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-05-26 00:19:40 +0200'>2020-05-26</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=cbec994ddef92cac0a6fd3640d443437b4ab3935'>gnu: lxappearance: Don't use NAME in source URI.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-05-26 00:19:40 +0200'>2020-05-26</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=3dfb21f0d7fcdca0ec7f16029cbc5a63460664f3'>gnu: lxappearance: Update to 0.6.3.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-05-13 09:30:26 +0300'>2020-05-13</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=3c986a7dc268756c097212de958f046b29b76c1b'>mailmap: Update entries for Nikita.</a><span class='msg-avail'>...</span></td><td>nikita</td></tr>
<tr><td><span title='2020-05-08 16:11:26 +0200'>2020-05-08</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=7ee215dea9226518911774f35130323d602a8ba9'>gnu: spacefm: Fix functionality.</a><span class='msg-avail'>...</span></td><td>Raghav Gururajan</td></tr>
<tr><td><span title='2020-05-01 14:10:33 +0200'>2020-05-01</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=53e8b852e90ec91e66172ad49f019955d7137eb1'>gnu: spacefm: Fix privilege and disk management.</a><span class='msg-avail'>...</span></td><td>Raghav Gururajan</td></tr>
<tr><td><span title='2020-04-24 22:03:09 +0200'>2020-04-24</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=bf37b49cdd345bcedeb7142f61968d3a6e15e8d8'>gnu: spacefm: Add dependencies for extra functionality.</a><span class='msg-avail'>...</span></td><td>Raghav Gururajan</td></tr>
<tr><td><span title='2020-04-05 18:23:15 +0200'>2020-04-05</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=3a3d5e36b815fee9a9bac31f4b62e0b85744a298'>gnu: spacefm: Make some inputs native.</a><span class='msg-avail'>...</span></td><td>Vincent Legoll</td></tr>
<tr><td><span title='2020-02-12 04:44:22 +0100'>2020-02-12</span></td><td><a href='/guix/commit/gnu/packages/lxde.scm?id=28ee711152f04dc1fa049f15adafe7b10d1b7628'>gnu: spacefm: Use HTTPS home page.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>