error[E0703]: invalid ABI: found `fictional`
  --> $DIR/fictional-abi.rs:3:12
   |
LL | pub extern "fictional" fn lol() {}
   |            ^^^^^^^^^^^ invalid ABI
   |
   = note: invoke `rustc --print=calling-conventions` for a full list of supported calling conventions

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0703`.