https://bugs.gentoo.org/669128#c3

--- a/bash_completion
+++ b/bash_completion
@@ -2037,7 +2037,7 @@ _comp__init_set_up_service_completions
 _comp_compgen_kernel_modules()
 {
     local _modpath=/lib/modules/$1
-    _comp_compgen_split -- "$(command ls -RL "$_modpath" 2>/dev/null |
+    _comp_compgen_split -- "$(command ls -RL "$_modpath"/!(source|build) 2>/dev/null |
         command sed -ne 's/^\(.*\)\.k\{0,1\}o\(\.[gx]z\)\{0,1\}$/\1/p' \
             -e 's/^\(.*\)\.ko\.zst$/\1/p')"
 }