cargo rustc --release --bin justbot -- --emit link=JustBot-5CB83BD3-73F30F5B
   Compiling libc v0.2.189
   Compiling rand_core v0.10.1
   Compiling getrandom v0.4.3
   Compiling cfg-if v1.0.4
   Compiling cpufeatures v0.3.0
   Compiling justbot v0.5.0-dev (/tmp/tmpj9uwwmzy/JustBot/JustBot-tmp)
   Compiling chacha20 v0.10.1
   Compiling rand v0.10.2
error[E0658]: `if let` guards are experimental
  --> src/search/time.rs:82:59
   |
82 |             Limit::Fischer(_, _) | Limit::Cyclic(_, _, _) if let Some(limit) = self.soft_bound => {
   |                                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #51114 <https://github.com/rust-lang/rust/issues/51114> for more information
   = help: you can write `if matches!(<expr>, <pattern>)` instead of `if let <pattern> = <expr>`

error[E0658]: `if let` guards are experimental
  --> src/search/time.rs:85:29
   |
85 |             Limit::Exact(_) if let Some(limit) = self.soft_bound => self.elapsed() >= limit,
   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #51114 <https://github.com/rust-lang/rust/issues/51114> for more information
   = help: you can write `if matches!(<expr>, <pattern>)` instead of `if let <pattern> = <expr>`

error[E0658]: `if let` guards are experimental
  --> src/search/time.rs:98:17
   |
98 | /                 if let Some(limit) = self.hard_bound
99 | |                     && data.nodes().is_multiple_of(2048) =>
   | |________________________________________________________^
   |
   = note: see issue #51114 <https://github.com/rust-lang/rust/issues/51114> for more information
   = help: you can write `if matches!(<expr>, <pattern>)` instead of `if let <pattern> = <expr>`

For more information about this error, try `rustc --explain E0658`.
error: could not compile `justbot` (lib) due to 3 previous errors
make: *** [Makefile:16: build] Error 101