Perhaps even worse, even if you ask clang to produce a compiler warning for the undefined behavior with -Wnull-dereference you get nothing. At least gcc still does the right thing there:

The solution was: Nothing! It turns out that due to the undefined behavior of the NULL-pointer dereference in the beginning of main, clang's optimizer removes main entirely and you just get a call to _fini! No compile time warning, no runtime warning. All is fine in the land of C! 😜