error: expected one of `!`, `+`, `,`, `::`, or `>`, found `(`
  --> $DIR/deep-unmatched-angle-brackets.rs:14:63
   |
LL |         <f::<f::<f::<f::<f::<f::<f::<f::<f::<f::<f::<f::<f::<>();
   |                                                               ^ expected one of `!`, `+`, `,`, `::`, or `>`
   |
help: you might have meant to end the type parameters here
   |
LL |         <f::<f::<f::<f::<f::<f::<f::<f::<f::<f::<f::<f::<f::<>>();
   |                                                               +

error: aborting due to previous error