[INFO] updating cached repository ParkinWu/search_tree
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/ParkinWu/search_tree
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/ParkinWu/search_tree" "work/ex/beta-1.38-1/sources/1.37.0/gh/ParkinWu/search_tree"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/ParkinWu/search_tree'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/ParkinWu/search_tree" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/ParkinWu/search_tree"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/ParkinWu/search_tree'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 1150f31d3a8e45ad85e0cf6389803ddb6d371521
[INFO] sha for GitHub repo ParkinWu/search_tree: 1150f31d3a8e45ad85e0cf6389803ddb6d371521
[INFO] validating manifest of ParkinWu/search_tree on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of ParkinWu/search_tree on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing ParkinWu/search_tree
[INFO] finished frobbing ParkinWu/search_tree
[INFO] frobbed toml for ParkinWu/search_tree written to work/ex/beta-1.38-1/sources/1.37.0/gh/ParkinWu/search_tree/Cargo.toml
[INFO] started frobbing ParkinWu/search_tree
[INFO] finished frobbing ParkinWu/search_tree
[INFO] frobbed toml for ParkinWu/search_tree written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/ParkinWu/search_tree/Cargo.toml
[INFO] crate ParkinWu/search_tree already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] error: the lock file /mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/ParkinWu/search_tree/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing ParkinWu/search_tree against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-3/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/ParkinWu/search_tree:/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-2019-08-13" "build" "--frozen"`
[INFO] [stdout] 6eed5c8865514cef03755eb97dd2a878e8679ce0194f5c613e25afaa2d9e3ae2
[INFO] running `"docker" "start" "-a" "6eed5c8865514cef03755eb97dd2a878e8679ce0194f5c613e25afaa2d9e3ae2"`
[INFO] [stderr]    Compiling binary_tree v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `Formatter`
[INFO] [stderr]  --> src/main.rs:4:24
[INFO] [stderr]   |
[INFO] [stderr] 4 | use std::fmt::{ Debug, Formatter};
[INFO] [stderr]   |                        ^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `take_next`
[INFO] [stderr]   --> src/main.rs:58:5
[INFO] [stderr]    |
[INFO] [stderr] 58 |     fn take_next(&mut self) -> Option<Box<Self>> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `pop_back`
[INFO] [stderr]   --> src/main.rs:90:5
[INFO] [stderr]    |
[INFO] [stderr] 90 |     fn pop_back(&mut self) -> Option<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push_front`
[INFO] [stderr]    --> src/main.rs:103:5
[INFO] [stderr]     |
[INFO] [stderr] 103 |     fn push_front(&mut self, elem: T) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `pop_front`
[INFO] [stderr]    --> src/main.rs:113:5
[INFO] [stderr]     |
[INFO] [stderr] 113 |     fn pop_front(&mut self) -> Option<T> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `iter`
[INFO] [stderr]    --> src/main.rs:127:5
[INFO] [stderr]     |
[INFO] [stderr] 127 |     fn iter(&self) -> Iter<T> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Iter`
[INFO] [stderr]    --> src/main.rs:159:1
[INFO] [stderr]     |
[INFO] [stderr] 159 | struct Iter<'a, T: 'a> {
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.70s
[INFO] running `"docker" "inspect" "6eed5c8865514cef03755eb97dd2a878e8679ce0194f5c613e25afaa2d9e3ae2"`
[INFO] running `"docker" "rm" "-f" "6eed5c8865514cef03755eb97dd2a878e8679ce0194f5c613e25afaa2d9e3ae2"`
[INFO] [stdout] 6eed5c8865514cef03755eb97dd2a878e8679ce0194f5c613e25afaa2d9e3ae2
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-3/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/ParkinWu/search_tree:/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-2019-08-13" "test" "--frozen" "--no-run"`
[INFO] [stdout] 3ebfbc1bd086e0ee4f68d2323c954ba1911818bacb91f212af1a389c115fadfd
[INFO] running `"docker" "start" "-a" "3ebfbc1bd086e0ee4f68d2323c954ba1911818bacb91f212af1a389c115fadfd"`
[INFO] [stderr]    Compiling binary_tree v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `Formatter`
[INFO] [stderr]  --> src/main.rs:4:24
[INFO] [stderr]   |
[INFO] [stderr] 4 | use std::fmt::{ Debug, Formatter};
[INFO] [stderr]   |                        ^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `iter`
[INFO] [stderr]    --> src/main.rs:127:5
[INFO] [stderr]     |
[INFO] [stderr] 127 |     fn iter(&self) -> Iter<T> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Iter`
[INFO] [stderr]    --> src/main.rs:159:1
[INFO] [stderr]     |
[INFO] [stderr] 159 | struct Iter<'a, T: 'a> {
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.67s
[INFO] running `"docker" "inspect" "3ebfbc1bd086e0ee4f68d2323c954ba1911818bacb91f212af1a389c115fadfd"`
[INFO] running `"docker" "rm" "-f" "3ebfbc1bd086e0ee4f68d2323c954ba1911818bacb91f212af1a389c115fadfd"`
[INFO] [stdout] 3ebfbc1bd086e0ee4f68d2323c954ba1911818bacb91f212af1a389c115fadfd
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-3/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/ParkinWu/search_tree:/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-2019-08-13" "test" "--frozen"`
[INFO] [stdout] e55290ae2a77bc83f791c302635f223752c15a7ac8d3b16ca294e40b4ad80367
[INFO] running `"docker" "start" "-a" "e55290ae2a77bc83f791c302635f223752c15a7ac8d3b16ca294e40b4ad80367"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/binary_tree-9ba237093d94c15f
[INFO] [stdout] 
[INFO] [stdout] running 4 tests
[INFO] [stdout] test push_front_test ... ok
[INFO] [stdout] test pop_front_test ... ok
[INFO] [stdout] test push_front_back_test ... ok
[INFO] [stdout] test push_pop_test ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 4 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `"docker" "inspect" "e55290ae2a77bc83f791c302635f223752c15a7ac8d3b16ca294e40b4ad80367"`
[INFO] running `"docker" "rm" "-f" "e55290ae2a77bc83f791c302635f223752c15a7ac8d3b16ca294e40b4ad80367"`
[INFO] [stdout] e55290ae2a77bc83f791c302635f223752c15a7ac8d3b16ca294e40b4ad80367