more glossary entries

S99-glossary.pod

@@ -658,6 +658,9 @@ contexts.
 
 =head2 sanity test
 
+A test for a basic feature that robs your sanitfy if it doesn't work, and the
+fact that it doesn't work goes unnoticed.
+
 =head2 scalar
 
 =head2 segfault
@@ -795,6 +798,13 @@ This lemma will never be explained.
 
 =head1 X
 
+=head2 XY Problem
+
+Sometimes people want to achieve X, and think Y is the best way to do it. So
+they ask "How do I do Y?", but doing Y is actually harder or less idiomatic
+than solving X some other way. So the person asking how to do Y has an XY
+problem.
+
 =head1 Y
 
 =head2 yoleaux