The following package sources are also affected (i.e. they definitely use
XCreate.*Cursor, and have libx11 as direct input) on guix master (214 sources):

allegro-4.4.3.1
allegro-5.0.11
allegro-5.2.7.0
Aseprite-v1.1.7-Source.zip
awesome-4.3
blender-3.0.1
bochs-2.7
boinc-7.16.17-checkout
bsnes-115-checkout
bzflag-2.4.24
Cairo
carla-2.4.1-checkout
cgoban-1.9.14
chromium-98.0.4758.102
cl-sdl2-0.0.0-1.bb2aa2a-checkout
clutter-1.26.2
cwm-6.7
directfb-1.7.7-checkout
dmenu-5.1
dolphin-emu-5.0-13178.a34823d-checkout
drawterm-20210628-1.c97fe46-checkout
dwm-6.3
editres-1.0.7
edk2-20170116-1.13a50a6-checkout
efl-1.26.2
emacs-27.2
emacs-next-28.0.50-0.2ea3466-checkout
emacs-next-pgtk-28.0.50-1.ae18c8e-checkout
EMBOSS-6.5.7
evilwm-1.3.1
exim-4.95
fbida-2.14
feh-3.8
ffmpeg-2.8.18
firefox-78.15.0
fltk-1.3.6
fluida-lv2-0.6-checkout
fluxbox-1.3.7
fontforge-20190801
fontforge-20201107
fox-1.6.57
freeglut-2.8.1
freeglut-3.2.1
freerdp-2.2.0-checkout
fvwm-2.6.9
ghostscript-9.54.0
gifsicle-1.93
gimp-2.10.30
glfw-3.3.4
glimpse-0.2.0-checkout
gmic-3.0.0
gnuplot-5.4.2
godot-3.4.2-checkout
GraphicsMagick-1.3.36
graphviz-2.38.0-1.f54ac2c-checkout
graphviz-2.49.0
gr-framework-0.58.1-checkout
gromacs-2020.2
gtk+-2.24.33
gtk+-3.24.30
gtk-4.4.1
guile-emacs-0.0.0-0.41120e0-checkout
helm-0.9.0-checkout
herbstluftwm-0.9.3
higan-110-checkout
hwloc-1.11.12
hwloc-2.7.1
idesk-0.7.5
ImageMagick-6.9.12-4
imager
irrlicht-1.8.4
java-openjfx-build-8.202-checkout
jdk-0276cba45aac
jdk-11.0.13-ga
jdk-3cc80be736f2
jdk-6fa770f9f8ab
jgmenu-4.4.0-checkout
kitty-0.20.3-checkout
kodi-18.8-checkout
lesstif-0.95.2
libcaca-0.99.beta19
libreoffice-7.1.4.2
libresprite-1.0-checkout
libXcursor-1.2.0
libXmu-1.1.3
libXt-1.2.1
looking-glass-client-B5-checkout
lsp-plugins-1.1.26-checkout
lukesmithxyz-st-0.8.4-checkout
lush-2.0.1
lyx-2.3.6.1
mamba-2.1-checkout
marco-1.24.1
mlterm-3.9.1
mono-4.4.1
mpich-3.3.2
MPlayer-1.4
mpv-0.34.1-checkout
mupdf-1.19.0-source
mutter-41.0
netpbm-10.78.3-checkout
ngspice-36
nsxiv-27.1-checkout
ntk-1.3.1000-checkout
ois-1.5.1-checkout
oneko-1.2.sakura.5
openbox-3.6.1
opencpn-5.6.0-checkout
openjdk-13.0.7-checkout
openjdk-14.0.2-checkout
openjdk-15.0.3-checkout
openjdk-16.0.1-checkout
openjdk-17.0.1-checkout
openscenegraph-3.6.5-checkout
patchmatrix-0.16.0-checkout
pcb-4.0.2
pcb-rnd-2.2.4
pcsxr-6484236cb0281e8040ff6c8078c87899a3407534-checkout
petsc-3.16.1
plib-1.8.5
polyml-5.8.2-checkout
povray-3.7.0.8-checkout
psi-1.5
psi-plus-1.5.1484-checkout
qemu-4.1.0
qemu-6.2.0
qtbase-everywhere-src-5.15.2
qtbase-everywhere-src-6.1.1
qtwebengine-everywhere-src-5.15.2
R-4.1.2
ratpoison-1.4.9
redkite-1.3.1-checkout
retroarch-1.9.11-checkout
ring-project
rxvt-unicode-9.30
sawfish_1.12.0
scrot-1.7-checkout
SDL-1.2.15
SDL2-2.0.14
SDL2_image-2.0.5
sent-1.tar.gz
sfml-2.5.1-checkout
sherlock.lv2-0.24.0
slim-1.3.6
slock-1.4
slop-7.6-checkout
snd-20.9
Squeak-4.10.2.2614-src
st-0.8.5
stalin-0.11-checkout
stepmania-5.1.0-b2-checkout
SuperTuxKart-1.3-src
swi-prolog-8.3.20-checkout
sxiv-26-checkout
synergy-1.11.1-checkout
tcltk2
texlive-20210325-source
TeXmacs-2.1.1-src
TiMidity++-2.15.0
Tk-804.036
tk8.6.11
tklib-0.6
transset-1.0.2
trayer-srg-1.1.8-checkout
tvtime-1.0.11
twm-1.0.11
unclutter
utox-0.18.1-checkout
vim-8.2.4564-checkout
virtualgl-2.6.2-checkout
VTK-6.3.0
VTK-9.0.1
warsow-qfusion-2.5-1.c4de15d-checkout
WindowMaker-0.95.9
wine-6.6
wine-7.0
winit-0.19.5
winit-0.20.0-alpha6
winit-0.24.0
wmctrl-1.07
wolf-shaper-0.1.8-checkout
wolf-spectrum-1.0.0-checkout
wxGTK-2.8.12
wxPython-src-3.0.2.0
wxWidgets-3.0.5.1
wxwidgets-3.1.5-checkout
X11-1.10.2
xarcan-0.5.4-1.8e6ee02-checkout
xboard-4.9.1
xdotool-3.20211022.1
xf86-video-intel-2.99.917-18.31486f4-checkout
xfce4-taskmanager-1.4.2
xfe-1.44
xfig-3.2.8b
Xfoil
xfwm4-4.16.1
xkill-1.0.5
xlispstat-3.52.23-0.f1bea60-checkout
xlockmore-5.68
xmag-1.0.6
Xonotic
xorg-server-21.1.2
xournalpp-1.1.1-checkout
xprop-1.2.5
xscreensaver-5.45
xsecurelock-1.7.0
xsetroot-1.1.2
xshogi-1.4.2
xsnow-3.4.2
xst-0.8.4.1-checkout
xterm-370
xwd-1.0.8
xwininfo-1.1.5
zbar-0.23.90-checkout

Of those, only the following use Xcursor.h already (who knows what they use
it for--but at least it's there):

allegro-4.4.3.1
allegro-5.0.11
allegro-5.2.7.0
Aseprite-v1.1.7-Source.zip
carla-2.4.1-checkout
chromium-98.0.4758.102
efl-1.26.2
fltk-1.3.6 (explicit -lXcursor)
fontforge-20201107
fox-1.6.57 (explicit -lXcursor)
freerdp
fvwm-2.6.9 (explicit -lXcursor)
gimp-2.10.30
glfw-3.3.4
glimpse-0.2.0
godot-3.4.2
gr-framework-0.58.1-checkout (only explicit -lXcursor, no .h)
gtk+-2.24.33
gtk+-3.24.30
gtk-4.4.1
helm-0.9.0
irrlicht-1.8.4 (explicit -lXcursor)
kitty-0.20.3
libresprite-1.0-checkout
looking-glass-client-B5
marco-1.24.1
mutter-41.0
openbox-3.6.1
qtbase-everywhere-src-5.15.2
qtbase-everywhere-src-6.1.1
qtwebengine-everywhere-src-5.15.2
SDL2-2.0.14 (explicit -lXcursor)
SuperTuxKart-1.3-src (bundled irrlicht)
VTK-9.0.1
wine-6.6 (explicit -lXcursor)
wine-7.0 (explicit -lXcursor)
xf86-video-intel-2.99.917-18.31486f4-checkout
xsetroot-1.1.2

Of the former, Cairo is the most worrying.

Details attached.