This patch comes from upstream:
https://gitlab.freedesktop.org/farstream/farstream/-/merge_requests/4

From 54987d445ea714b467d901b7daf8c09ed0644189 Mon Sep 17 00:00:00 2001
From: Debarshi Ray <debarshir@freedesktop.org>
Date: Thu, 12 Mar 2020 14:07:23 +0100
Subject: [PATCH] build: Adapt to backwards incompatible change in GNU Make 4.3

GNU Make 4.3 has a backwards incompatible change affecting the use of
number signs or hashes (ie., #) inside function invocations. See:
https://lists.gnu.org/archive/html/info-gnu/2020-01/msg00004.html

In this case, it would expand the '\#' in the '\n\#include \"$(h)\"'
argument to the foreach call to '\#', not '#'. This would lead to
spurious backslashes in front of the '#include' directives in the
generated fs-enumtypes.c file.

Spotted by Ernestas Kulik.
---
 common-modified/gst-glib-gen.mak | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/common-modified/gst-glib-gen.mak b/common-modified/gst-glib-gen.mak
index 14f1ba37..2247a41c 100644
--- a/common-modified/gst-glib-gen.mak
+++ b/common-modified/gst-glib-gen.mak
@@ -6,7 +6,8 @@
 #glib_gen_prefix=gst_color_balance
 #glib_gen_basename=colorbalance
 
-enum_headers=$(foreach h,$(glib_enum_headers),\n\#include \"$(h)\")
+hash:=\#
+enum_headers=$(foreach h,$(glib_enum_headers),\n$(hash)include \"$(h)\")
 
 # these are all the rules generating the relevant files
 $(glib_gen_basename)-enumtypes.h: $(glib_enum_headers)
-- 
GitLab

ces/dns.scm?id=bb7c3d5aa3fceb08b0cc6403908bf8731d163745'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/services/dns.scm'>
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<div class='path'>path: <a href='/guix/log/?id=bb7c3d5aa3fceb08b0cc6403908bf8731d163745'>root</a>/<a href='/guix/log/gnu?id=bb7c3d5aa3fceb08b0cc6403908bf8731d163745'>gnu</a>/<a href='/guix/log/gnu/services?id=bb7c3d5aa3fceb08b0cc6403908bf8731d163745'>services</a>/<a href='/guix/log/gnu/services/dns.scm?id=bb7c3d5aa3fceb08b0cc6403908bf8731d163745'>dns.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/services/dns.scm?id=bb7c3d5aa3fceb08b0cc6403908bf8731d163745&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-10-06 08:13:39 +0200'>2020-10-06</span></td><td><a href='/guix/commit/gnu/services/dns.scm?id=34d1c0a03b51fdaef26a3bc630ab096da740e1d6'>services: dnsmasq: Add TFTP configuration fields.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/services/dns.scm (&lt;dnsmasq-configuration&gt;): Add TFTP configuration
fields.
(dnsmasq-shepherd-service): Use them.
* doc/guix.texi (DNS Services): Document them.
</span></span></td><td>Danny Milosavljevic</td></tr>
<tr><td><span title='2020-05-08 16:30:50 +0200'>2020-05-08</span></td><td><a href='/guix/commit/gnu/services/dns.scm?id=dd0804c67e99914eecc471fdb92f4220425a1cbc'>services: Add descriptions.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/services/dbus.scm (polkit-service-type)[description]: New field.
* gnu/services/dict.scm (dicod-service-type)[description]: New field.
* gnu/services/dns.scm (knot-service-type)[description]: New field.
* gnu/services/networking.scm (dhcpd-service-type)[description]: New field.
* gnu/services/shepherd.scm (shepherd-root-service-type)[description]:
New field.
* gnu/services/xorg.scm (slim-service-type)[description]: New field.
(screen-locker-service-type)[description]: New field.
* gnu/system/pam.scm (pam-root-service-type)[description]: New field.
* gnu/system/shadow.scm (account-service-type)[description]: New field.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-05-02 13:00:24 +0800'>2020-05-02</span></td><td><a href='/guix/commit/gnu/services/dns.scm?id=5a0b78e62bc3122998990cea5ee17bdb2789aada'>services: dnsmasq: Support the --address flag.</a><span class='msg-avail'>...<span class='msg-tooltip'>Introduce a new `addresses' field that translates to passing `--address='
multiple times to dnsmasq.

* gnu/services/dns.scm (&lt;dnsmasq-configuration&gt;): Add an addresses field.
(dnsmasq-shepherd-service): Match the addresses field and translate it to
multiple '--address=' flags.
* doc/guix.texi (DNS Services): Document it.

Signed-off-by: 宋文武 &lt;iyzsong@member.fsf.org&gt;
</span></span></td><td>Pierre Langlois</td></tr>