diff --git a/hosts/common/programs/signal-desktop.nix b/hosts/common/programs/signal-desktop.nix
index feac41c5..04a451a1 100644
--- a/hosts/common/programs/signal-desktop.nix
+++ b/hosts/common/programs/signal-desktop.nix
@@ -1,3 +1,10 @@
+# TODO(bug): signal-desktop is known to hang on exit.
+# particularly, it may fail to start (because e.g. there's no wayland session yet),
+# and it will try to exit -- after which the service would restart -- but it hangs w/ no GUI instead.
+# characterized by these log messages:
+#
+#     Dec 03 13:46:23 moby signal-desktop[4097]: [4097:1203/134623.906367:ERROR:ozone_platform_x11.cc(240)] Missing X server or $DISPLAY
+#     Dec 03 13:46:23 moby signal-desktop[4097]: [4097:1203/134623.909667:ERROR:env.cc(255)] The platform failed to initialize.  Exiting.
 { config, lib, pkgs, ... }:
 let
   cfg = config.sane.programs.signal-desktop;