diff -r e5998f53f4ff -r 02292b892fce mod_debug_traceback/mod_debug_traceback.lua
--- a/mod_debug_traceback/mod_debug_traceback.lua	Mon Oct 19 16:31:01 2020 +0200
+++ b/mod_debug_traceback/mod_debug_traceback.lua	Mon Oct 19 15:47:25 2020 +0100
@@ -47,7 +47,7 @@
 end
 
 local mod_posix = module:depends("posix");
-if mod_posix.features and mod_posix.features.signal_events then
+if rawget(mod_posix, "features") and mod_posix.features.signal_events then
 	module:hook("signal/"..signal_name, dump_traceback);
 else
 	require"util.signal".signal(signal_name, dump_traceback);