[INFO] crate avl_tree 0.2.0 is already in cache
[INFO] extracting crate avl_tree 0.2.0 into work/ex/beta-1.37-6/sources/1.36.0/reg/avl_tree/0.2.0
[INFO] extracting crate avl_tree 0.2.0 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/avl_tree/0.2.0
[INFO] validating manifest of avl_tree-0.2.0 on toolchain 1.36.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of avl_tree-0.2.0 on toolchain beta-2019-07-23
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing avl_tree-0.2.0
[INFO] finished frobbing avl_tree-0.2.0
[INFO] frobbed toml for avl_tree-0.2.0 written to work/ex/beta-1.37-6/sources/1.36.0/reg/avl_tree/0.2.0/Cargo.toml
[INFO] started frobbing avl_tree-0.2.0
[INFO] finished frobbing avl_tree-0.2.0
[INFO] frobbed toml for avl_tree-0.2.0 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/avl_tree/0.2.0/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing avl_tree-0.2.0 against beta-2019-07-23 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-7/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/avl_tree/0.2.0:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+beta-2019-07-23" "build" "--frozen"`
[INFO] [stdout] e0b9d4fd73389f1b9413e881c9464411f25fd1bbaa7a8b7583b333fc88278b93
[INFO] running `"docker" "start" "-a" "e0b9d4fd73389f1b9413e881c9464411f25fd1bbaa7a8b7583b333fc88278b93"`
[INFO] [stderr]    Compiling avl_tree v0.2.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | #![feature(test)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:4:1
[INFO] [stderr]   |
[INFO] [stderr] 4 | #![feature(collections_bound)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:5:1
[INFO] [stderr]   |
[INFO] [stderr] 5 | #![feature(rand)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around function argument
[INFO] [stderr]    --> src/node.rs:252:20
[INFO] [stderr]     |
[INFO] [stderr] 252 |         t = insert((x as u64),1337+x-1,t)
[INFO] [stderr]     |                    ^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_parens)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `max`, `min`, `to_string`
[INFO] [stderr]  --> src/tree.rs:5:33
[INFO] [stderr]   |
[INFO] [stderr] 5 | use node::{insert,delete,search,min,max,is_avl_tree, to_string, min_pair, max_pair};
[INFO] [stderr]   |                                 ^^^ ^^^              ^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 3 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `avl_tree`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "e0b9d4fd73389f1b9413e881c9464411f25fd1bbaa7a8b7583b333fc88278b93"`
[INFO] running `"docker" "rm" "-f" "e0b9d4fd73389f1b9413e881c9464411f25fd1bbaa7a8b7583b333fc88278b93"`
[INFO] [stdout] e0b9d4fd73389f1b9413e881c9464411f25fd1bbaa7a8b7583b333fc88278b93