When providing the VNCServer command as 'Xvnc -SecurityTypes None',
the formatted command line used would look like:

  Xvnc  -SecurityTypes None :1 -auth /var/run/lightdm/root/:1

which is invalid (the display number must appear first).

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

 src/x-server-local.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/x-server-local.c b/src/x-server-local.c
index 7c4ab870..6c540d18 100644
--- a/src/x-server-local.c
+++ b/src/x-server-local.c
@@ -463,14 +463,20 @@ x_server_local_start (DisplayServer *display_server)
     l_debug (display_server, "Logging to %s", log_file);
 
     g_autofree gchar *absolute_command = get_absolute_command (priv->command);
+    g_auto(GStrv) tokens = g_strsplit (absolute_command, " ", 2);
+    const gchar* binary = tokens[0];
+    const gchar *extra_options = tokens[1];
+
     if (!absolute_command)
     {
         l_debug (display_server, "Can't launch X server %s, not found in path", priv->command);
         stopped_cb (priv->x_server_process, X_SERVER_LOCAL (server));
         return FALSE;
     }
-    g_autoptr(GString) command = g_string_new (absolute_command);
+    g_autoptr(GString) command = g_string_new (binary);
 
+    /* The display argument must be given first when the X server used
+     * is Xvnc. */
     g_string_append_printf (command, " :%d", priv->display_number);
 
     if (priv->config_file)
@@ -513,6 +519,12 @@ x_server_local_start (DisplayServer *display_server)
     if (X_SERVER_LOCAL_GET_CLASS (server)->add_args)
         X_SERVER_LOCAL_GET_CLASS (server)->add_args (server, command);
 
+    /* Any extra user options provided via the VNCServer 'command'
+     * config option are appended last, so the user can override any
+     * of the above. */
+    if (extra_options)
+        g_string_append_printf (command, " %s", extra_options);
+
     process_set_command (priv->x_server_process, command->str);
 
     l_debug (display_server, "Launching X Server");
-- 
2.36.1

10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=2d0f081f2d7bde6c11d932bf2ff5801524e15aa2&amp;showmsg=1'>root</a>/<a href='/guix/log/etc?id=2d0f081f2d7bde6c11d932bf2ff5801524e15aa2&amp;showmsg=1'>etc</a>/<a href='/guix/log/etc/init.d?id=2d0f081f2d7bde6c11d932bf2ff5801524e15aa2&amp;showmsg=1'>init.d</a>/<a href='/guix/log/etc/init.d/guix-daemon.in?id=2d0f081f2d7bde6c11d932bf2ff5801524e15aa2&amp;showmsg=1'>guix-daemon.in</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/etc/init.d/guix-daemon.in?id=2d0f081f2d7bde6c11d932bf2ff5801524e15aa2'>Collapse</a>)</th><th class='left'>Author</th></tr>
<tr class='logheader'><td><span title='2021-07-07 23:54:20 -0400'>2021-07-07</span></td><td class='logsubject'><a href='/guix/commit/etc/init.d/guix-daemon.in?id=4cbe0127a668cbcc64087c5d311308b59d39b104'>guix-install.sh: Prompt for configuring substitutes discovery.</a></td><td>Maxim Cournoyer</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
Also ensure prompt_yes_no always print the message with a trailing space,
which is more pleasing to the eye.

* etc/guix-daemon.conf.in &lt;--discover=no&gt;: New guix-daemon option.
* etc/guix-daemon.service.in: Likewise.
* etc/init.d/guix-daemon.in: Likewise.
* etc/openrc/guix-daemon.in: Likewise.
* etc/guix-install.sh (configure_substitute_discovery): New procedure.
(sys_enable_guix_daemon): Ask the user whether automatic substitute discovery
should be enabled.  Set the '--discover' argument accordingly.
(prompt_yes_no): Add a trailing space to the message.
(sys_authorize_build_farms): Remove trailing space from the message argument.
* NEWS (Distribution): Add news.


</td></tr>
<tr class='logheader'><td><span title='2020-03-11 02:45:33 +0100'>2020-03-11</span></td><td class='logsubject'><a href='/guix/commit/etc/init.d/guix-daemon.in?id=73fbe04107d38f4561636c74d28d7a4935cbb1ef'>Add system start-up files for guix-daemon.</a></td><td>Danny Milosavljevic</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* etc/init.d/guix-daemon.in: New file.
* nix/local.mk (etc/init.d/guix-daemon): New rule.
(nodist_sysvinitservice_DATA): Add etc/init.d/guix-daemon.in .
(CLEANFILES): Add etc/init.d/guix-daemon .
* .gitignore: Add etc/init.d/guix-daemon .


</td></tr>
vic Courtès</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* etc/time-travel-manifest.scm (guix-instance-compiler): Parameterize
%REPOSITORY-CACHE-DIRECTORY.


</td></tr>
<tr class='logheader'><td><span title='2022-07-08 23:58:11 +0200'>2022-07-08</span></td><td class='logsubject'><a href='/guix/commit/etc/time-travel-manifest.scm?id=e80f0cda96181d90604c44f69094f2499036b3f6'>etc: Add 'time-travel-manifest.scm'.</a></td><td>Ludovic Courtès</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
This manifest makes it easy to test travels from the current revision
back to the revision of a past Guix release.

Suggested by zimoun &lt;zimon.toutoune@gmail.com&gt;.

* etc/time-travel-manifest.scm: New file.
* Makefile.am (EXTRA_DIST): Add it.


</td></tr>