error[E0080]: calling a function with calling convention "C" using calling convention "Rust"
  --> $DIR/abi-mismatch.rs:11:18
   |
LL | static VAL: () = call_rust_fn(unsafe { std::mem::transmute(c_fn as extern "C" fn()) });
   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `VAL` failed inside this call
   |
note: inside `call_rust_fn`
  --> $DIR/abi-mismatch.rs:7:5
   |
LL |     my_fn();
   |     ^^^^^^^ the failure occurred here

warning: skipping const checks
   |
help: skipping check that does not even have a feature gate
  --> $DIR/abi-mismatch.rs:7:5
   |
LL |     my_fn();
   |     ^^^^^^^

error: aborting due to 1 previous error; 1 warning emitted

For more information about this error, try `rustc --explain E0080`.