cargo install racer error

[Neping]

rust version: rustc 1.49.0-nightly (ffa2e7ae8 2020-10-24)

error: error[E0107]: wrong number of type arguments: expected 2, found 1 --> /Users/bruse/.cargo/registry/src/github.com-1ecc6299db9ec823/rustc-ap-rustc_data_structures-686.0.0/src/graph/iterate/mod.rs:256:10 | 256 | ) -> ControlFlow { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 2 type arguments

error[E0107]: wrong number of type arguments: expected 2, found 1 --> /Users/bruse/.cargo/registry/src/github.com-1ecc6299db9ec823/rustc-ap-rustc_data_structures-686.0.0/src/graph/iterate/mod.rs:261:51 | 261 | fn node_settled(&mut self, _node: G::Node) -> ControlFlow { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 2 type arguments

error[E0107]: wrong number of type arguments: expected 2, found 1 --> /Users/bruse/.cargo/registry/src/github.com-1ecc6299db9ec823/rustc-ap-rustc_data_structures-686.0.0/src/graph/iterate/mod.rs:284:10 | 284 | ) -> ControlFlow { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 2 type arguments

error: aborting due to 3 previous errors

For more information about this error, try rustc --explain E0107. error: could not compile rustc-ap-rustc_data_structures

To learn more, run the command again with --verbose. warning: build failed, waiting for other jobs to finish... error: failed to compile racer v2.1.40, intermediate artifacts can be found at /var/folders/bx/_zcqpz9116n4gv7xkncjghqw0000gn/T/cargo-installTsxEbJ

Caused by: build failed