There is no longer support for 8 bit color depth in TigerVNC (see:
https://github.com/TigerVNC/tigervnc/commit/e86d8720ba1e79b486ca29a5c2b27fa25811e6a2);
using it causes a fatal error.

Submitted upstream at: https://github.com/canonical/lightdm/pull/265.

diff --git a/data/lightdm.conf b/data/lightdm.conf
index 0df38429..60e3e8b4 100644
--- a/data/lightdm.conf
+++ b/data/lightdm.conf
@@ -160,4 +160,4 @@
 #listen-address=
 #width=1024
 #height=768
-#depth=8
+#depth=24
diff --git a/src/x-server-xvnc.c b/src/x-server-xvnc.c
index 68340d53..27ca4454 100644
--- a/src/x-server-xvnc.c
+++ b/src/x-server-xvnc.c
@@ -127,7 +127,7 @@ x_server_xvnc_init (XServerXVNC *server)
     XServerXVNCPrivate *priv = x_server_xvnc_get_instance_private (server);
     priv->width = 1024;
     priv->height = 768;
-    priv->depth = 8;
+    priv->depth = 24;
 }
 
 static void
diff --git a/tests/scripts/vnc-command.conf b/tests/scripts/vnc-command.conf
index 0f1e25fd..335956d9 100644
--- a/tests/scripts/vnc-command.conf
+++ b/tests/scripts/vnc-command.conf
@@ -19,7 +19,7 @@ command=Xvnc -option
 #?VNC-CLIENT CONNECT
 
 # Xvnc server starts
-#?XVNC-0 START GEOMETRY=1024x768 DEPTH=8 OPTION=TRUE
+#?XVNC-0 START GEOMETRY=1024x768 DEPTH=24 OPTION=TRUE
 
 # Daemon connects when X server is ready
 #?*XVNC-0 INDICATE-READY
diff --git a/tests/scripts/vnc-guest.conf b/tests/scripts/vnc-guest.conf
index 431bb244..ce2b97db 100644
--- a/tests/scripts/vnc-guest.conf
+++ b/tests/scripts/vnc-guest.conf
@@ -21,7 +21,7 @@ user-session=default
 #?VNC-CLIENT CONNECT
 
 # Xvnc server starts
-#?XVNC-0 START GEOMETRY=1024x768 DEPTH=8 OPTION=FALSE
+#?XVNC-0 START GEOMETRY=1024x768 DEPTH=24 OPTION=FALSE
 
 # Daemon connects when X server is ready
 #?*XVNC-0 INDICATE-READY
diff --git a/tests/scripts/vnc-login.conf b/tests/scripts/vnc-login.conf
index cdfe17b8..f0d65b7f 100644
--- a/tests/scripts/vnc-login.conf
+++ b/tests/scripts/vnc-login.conf
@@ -21,7 +21,7 @@ user-session=default
 #?VNC-CLIENT CONNECT
 
 # Xvnc server starts
-#?XVNC-0 START GEOMETRY=1024x768 DEPTH=8 OPTION=FALSE
+#?XVNC-0 START GEOMETRY=1024x768 DEPTH=24 OPTION=FALSE
 
 # Daemon connects when X server is ready
 #?*XVNC-0 INDICATE-READY
diff --git a/tests/scripts/vnc-open-file-descriptors.conf b/tests/scripts/vnc-open-file-descriptors.conf
index 753c84dd..e5d35730 100644
--- a/tests/scripts/vnc-open-file-descriptors.conf
+++ b/tests/scripts/vnc-open-file-descriptors.conf
@@ -21,7 +21,7 @@ user-session=default
 #?VNC-CLIENT CONNECT
 
 # Xvnc server starts
-#?XVNC-0 START GEOMETRY=1024x768 DEPTH=8 OPTION=FALSE
+#?XVNC-0 START GEOMETRY=1024x768 DEPTH=24 OPTION=FALSE
 
 # Daemon connects when X server is ready
 #?*XVNC-0 INDICATE-READY
ch?id=cdbd81ce144f17644ceebd3d08723aa244696a05'>rust-1.64-fix-riscv64-bootstrap.patch</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/patches/rust-1.64-fix-riscv64-bootstrap.patch?id=cdbd81ce144f17644ceebd3d08723aa244696a05&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-11-29 15:11:52 +0200'>2022-11-29</span></td><td><a href='/guix/commit/gnu/packages/patches/rust-1.64-fix-riscv64-bootstrap.patch?id=36b993cd5b7088513d771fc2140c56327555c89b'>gnu: rust-1.64: Fix building on riscv64-linux.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/rust.scm (rust-1.64)[source]: Add patch and patch-flags.
(rust-1.65)[source]: Remove patch and reset patch-flags.
* gnu/packages/patches/rust-1.64-fix-riscv64-bootstrap.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.
</span></span></td><td>Efraim Flashner</td></tr>