I am uploading a NMU with the attached changes to fix this issue.
diff -Nru lxpanel-0.10.1/debian/changelog lxpanel-0.10.1/debian/changelog
--- lxpanel-0.10.1/debian/changelog 2023-09-16 02:17:33.000000000 +0000
+++ lxpanel-0.10.1/debian/changelog 2025-04-03 20:00:17.000000000 +0000
@@ -1,3 +1,10 @@
+lxpanel (0.10.1-4.1) unstable; urgency=medium
+
+ * Non-maintainer upload.
+ * Build with gcc-14 (Closes: #1075243).
+
+ -- Bastian Germann <b...@barriere.debian.org> Thu, 03 Apr 2025 20:00:17 +0000
+
lxpanel (0.10.1-4) unstable; urgency=medium
* Merge to unstable.
diff -Nru lxpanel-0.10.1/debian/patches/02-gcc14.patch
lxpanel-0.10.1/debian/patches/02-gcc14.patch
--- lxpanel-0.10.1/debian/patches/02-gcc14.patch 1970-01-01
00:00:00.000000000 +0000
+++ lxpanel-0.10.1/debian/patches/02-gcc14.patch 2025-04-03
19:54:18.000000000 +0000
@@ -0,0 +1,19 @@
+Origin: upstream, 0853b0fc981285ebd2ac52f8dfc2a09b1090748c
+From: Ravi Kant Sharma <600723+raviksha...@users.noreply.github.com>
+Date: Tue, 30 Jul 2024 17:52:07 +0200
+Subject: Fix gcc-14 build error
+
+gcc-14 now treats a conversion between pointers of incompatible types
+as an error.
+---
+--- a/plugins/tray.c
++++ b/plugins/tray.c
+@@ -631,7 +631,7 @@ static GtkWidget *tray_constructor(LXPanel *panel,
config_setting_t *settings)
+ /* Add GDK event filter. */
+ gdk_window_add_filter(NULL, (GdkFilterFunc) tray_event_filter, tr);
+ /* Reference the window since it is never added to a container. */
+- tr->invisible = g_object_ref_sink(G_OBJECT(invisible));
++ tr->invisible = GTK_WIDGET(g_object_ref_sink(G_OBJECT(invisible)));
+ tr->invisible_window = GDK_WINDOW_XID(gtk_widget_get_window(invisible));
+
+ /* Allocate top level widget and set into Plugin widget pointer. */
diff -Nru lxpanel-0.10.1/debian/patches/series
lxpanel-0.10.1/debian/patches/series
--- lxpanel-0.10.1/debian/patches/series 2023-09-16 02:17:33.000000000
+0000
+++ lxpanel-0.10.1/debian/patches/series 2025-04-03 19:54:51.000000000
+0000
@@ -1 +1,2 @@
01-default-config.patch
+02-gcc14.patch
diff -Nru lxpanel-0.10.1/debian/rules lxpanel-0.10.1/debian/rules
--- lxpanel-0.10.1/debian/rules 2023-09-16 02:17:33.000000000 +0000
+++ lxpanel-0.10.1/debian/rules 2025-04-03 19:57:31.000000000 +0000
@@ -4,6 +4,7 @@
DEB_HOST_MULTIARCH ?= $(shell dpkg-architecture -qDEB_HOST_MULTIARCH)
export DEB_BUILD_MAINT_OPTIONS = hardening=+all
+export DEB_CFLAGS_MAINT_APPEND = -Wno-deprecated-declarations
%:
dh ${@}
