[INFO] fetching crate avl_tree 0.2.0...
[INFO] testing avl_tree-0.2.0 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate avl_tree 0.2.0 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate avl_tree 0.2.0 on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate avl_tree 0.2.0
[INFO] finished tweaking crates.io crate avl_tree 0.2.0
[INFO] tweaked toml for crates.io crate avl_tree 0.2.0 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 324dd1a67f616977559d2d956a5f5351e2802305e3bd2f094930ad2a7a733451
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "324dd1a67f616977559d2d956a5f5351e2802305e3bd2f094930ad2a7a733451", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "324dd1a67f616977559d2d956a5f5351e2802305e3bd2f094930ad2a7a733451", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "324dd1a67f616977559d2d956a5f5351e2802305e3bd2f094930ad2a7a733451", kill_on_drop: false }`
[INFO] [stdout] 324dd1a67f616977559d2d956a5f5351e2802305e3bd2f094930ad2a7a733451
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a93bfa1568e1f6f2f1474b7e649263df0ea54f99ca5a422e9060513c3601518a
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "a93bfa1568e1f6f2f1474b7e649263df0ea54f99ca5a422e9060513c3601518a", kill_on_drop: false }`
[INFO] [stderr]    Compiling getrandom v0.2.1
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling syn v1.0.57
[INFO] [stderr]    Compiling const_fn v0.4.4
[INFO] [stderr]    Compiling standback v0.2.14
[INFO] [stderr]    Compiling time v0.2.23
[INFO] [stderr]    Compiling rand_core v0.6.0
[INFO] [stderr]    Compiling rand_chacha v0.3.0
[INFO] [stderr]    Compiling rand v0.8.0
[INFO] [stderr]    Compiling time-macros-impl v0.1.1
[INFO] [stderr]    Compiling time-macros v0.1.1
[INFO] [stderr]    Compiling avl_tree v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:4:1
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(collections_bound)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![feature(rand)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around function argument
[INFO] [stdout]    --> src/node.rs:252:20
[INFO] [stdout]     |
[INFO] [stdout] 252 |         t = insert((x as u64),1337+x-1,t)
[INFO] [stdout]     |                    ^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `max`, `min`, `to_string`
[INFO] [stdout]  --> src/tree.rs:5:33
[INFO] [stdout]   |
[INFO] [stdout] 5 | use node::{insert,delete,search,min,max,is_avl_tree, to_string, min_pair, max_pair};
[INFO] [stdout]   |                                 ^^^ ^^^              ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `avl_tree`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "a93bfa1568e1f6f2f1474b7e649263df0ea54f99ca5a422e9060513c3601518a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a93bfa1568e1f6f2f1474b7e649263df0ea54f99ca5a422e9060513c3601518a", kill_on_drop: false }`
[INFO] [stdout] a93bfa1568e1f6f2f1474b7e649263df0ea54f99ca5a422e9060513c3601518a