warning: function cannot return without recursing
  --> $DIR/issue-83150.rs:10:1
   |
LL | fn func<T: Iterator<Item = u8>>(iter: &mut T) {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot return without recursing
LL |
LL |     func(&mut iter.map(|x| x + 1))
   |     ------------------------------ recursive call site
   |
   = help: a `loop` may express intention better if this is on purpose
   = note: `#[warn(unconditional_recursion)]` on by default

error[E0275]: overflow evaluating the requirement `Map<&mut std::ops::Range<u8>, {closure@$DIR/issue-83150.rs:12:24: 12:27}>: Iterator`
   |
   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_83150`)
   = note: required for `&mut Map<&mut Range<u8>, {closure@issue-83150.rs:12:24}>` to implement `Iterator`
   = note: 65 redundant requirements hidden
   = note: required for `&mut Map<&mut Map<&mut Map<&mut Map<&mut ..., ...>, ...>, ...>, ...>` to implement `Iterator`
   = note: the full name for the type has been written to '$TEST_BUILD_DIR/issue-83150.long-type-$LONG_TYPE_HASH.txt'
   = note: consider using `--verbose` to print the full type name to the console

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

For more information about this error, try `rustc --explain E0275`.