How to make a slow compile

[monkyyy]

once again dconf contains people who talk about compile speed as 
if it can be slow

What are they doing? Even my worse compile time abstraction was 
O(n^2) or maybe some awful string concatenation of an entire 
file; still effectively instant

Wheres a 1000 line file that does something meta programmingly 
useful that takes 5 minutes?

Do they lose track of what the compiler is even doing? Do they 
turn off the template recursion depth limit?