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

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<div class='path'>path: <a href='/guix/log/?id=26709726a80de2d22ab129ff49b38dc1600bf8b2'>root</a>/<a href='/guix/log/gnu?id=26709726a80de2d22ab129ff49b38dc1600bf8b2'>gnu</a>/<a href='/guix/log/gnu/packages?id=26709726a80de2d22ab129ff49b38dc1600bf8b2'>packages</a>/<a href='/guix/log/gnu/packages/jupyter.scm?id=26709726a80de2d22ab129ff49b38dc1600bf8b2'>jupyter.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/jupyter.scm?id=26709726a80de2d22ab129ff49b38dc1600bf8b2&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-10-25 16:58:40 +0200'>2023-10-25</span></td><td><a href='/guix/commit/gnu/packages/jupyter.scm?id=617bca2ab0b4f57c65873cf3858c6387ea775ab1'>gnu: Add python-jupyterlite-sphinx.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/jupyter.scm (python-jupyterlite-sphinx): New variable.

Change-Id: I182c98e0c47d28012882994824232c3473ba3dcd
</span></span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2023-10-25 16:58:40 +0200'>2023-10-25</span></td><td><a href='/guix/commit/gnu/packages/jupyter.scm?id=1b9a0135fb54076f695178eae9f65a6567745898'>gnu: Add python-jupyterlite-core.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/jupyter.scm (python-jupyterlite-core): New variable.

Change-Id: I3b015f7bbb45d9575280a5b8c01d67459d6f143e
</span></span></td><td>Ricardo Wurmus</td></tr>