error[E0560]: union `U` has no field named `principle`
  --> $DIR/union-suggest-field.rs:13:17
   |
LL |     let u = U { principle: 0 };
   |                 ^^^^^^^^^ help: a field with a similar name exists: `principal`

error[E0609]: no field `principial` on type `U`
  --> $DIR/union-suggest-field.rs:17:15
   |
LL |     let w = u.principial;
   |               ^^^^^^^^^^ help: a field with a similar name exists: `principal`

error[E0615]: attempted to take value of method `calculate` on type `U`
  --> $DIR/union-suggest-field.rs:21:15
   |
LL |     let y = u.calculate;
   |               ^^^^^^^^^ method, not a field
   |
help: use parentheses to call the method
   |
LL |     let y = u.calculate();
   |                        ++

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0560, E0609, E0615.
For more information about an error, try `rustc --explain E0560`.