[INFO] cloning repository https://github.com/p870613/rust-learn
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/p870613/rust-learn" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fp870613%2Frust-learn", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fp870613%2Frust-learn'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 59ce988c1d225b430c0f293c2f0e27fed1e28cfc
[INFO] testing p870613/rust-learn against master#62efba8a050c64249dab942951bb28f710208bc8 for pr-90799
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fp870613%2Frust-learn" "/workspace/builds/worker-55/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-55/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/p870613/rust-learn on toolchain 62efba8a050c64249dab942951bb28f710208bc8
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+62efba8a050c64249dab942951bb28f710208bc8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/p870613/rust-learn
[INFO] finished tweaking git repo https://github.com/p870613/rust-learn
[INFO] tweaked toml for git repo https://github.com/p870613/rust-learn written to /workspace/builds/worker-55/source/Cargo.toml
[INFO] crate git repo https://github.com/p870613/rust-learn already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+62efba8a050c64249dab942951bb28f710208bc8" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e8397a04204aaf8b9f284182a6f9e27a3c2e67044d0943b4415b160bfc957681" "/opt/rustwide/cargo-home/bin/cargo" "+62efba8a050c64249dab942951bb28f710208bc8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4c0ad449387a4c3535e949c02a498d19310764a8aa33cd3a122740a8f267145a
[INFO] running `Command { std: "docker" "start" "-a" "4c0ad449387a4c3535e949c02a498d19310764a8aa33cd3a122740a8f267145a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4c0ad449387a4c3535e949c02a498d19310764a8aa33cd3a122740a8f267145a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4c0ad449387a4c3535e949c02a498d19310764a8aa33cd3a122740a8f267145a", kill_on_drop: false }`
[INFO] [stdout] 4c0ad449387a4c3535e949c02a498d19310764a8aa33cd3a122740a8f267145a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/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=forbid" "-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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e8397a04204aaf8b9f284182a6f9e27a3c2e67044d0943b4415b160bfc957681" "/opt/rustwide/cargo-home/bin/cargo" "+62efba8a050c64249dab942951bb28f710208bc8" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a3a959ef49bd863ef86bcac6e54584abba91acc0dfe6adfeefb9cffebb746513
[INFO] running `Command { std: "docker" "start" "-a" "a3a959ef49bd863ef86bcac6e54584abba91acc0dfe6adfeefb9cffebb746513", kill_on_drop: false }`
[INFO] [stderr]    Compiling double_linked_list v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `tmp` is never read
[INFO] [stdout]    --> src/main.rs:236:13
[INFO] [stdout]     |
[INFO] [stdout] 236 |     let mut tmp = None;
[INFO] [stdout]     |             ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `tmp2` is never read
[INFO] [stdout]    --> src/main.rs:237:13
[INFO] [stdout]     |
[INFO] [stdout] 237 |     let mut tmp2 = None;
[INFO] [stdout]     |             ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `tmp3` is never read
[INFO] [stdout]    --> src/main.rs:238:13
[INFO] [stdout]     |
[INFO] [stdout] 238 |     let mut tmp3 = None;
[INFO] [stdout]     |             ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `del`
[INFO] [stdout]   --> src/main.rs:86:21
[INFO] [stdout]    |
[INFO] [stdout] 86 |                 let del = node.borrow_mut().next.take();
[INFO] [stdout]    |                     ^^^ help: if this is intentional, prefix it with an underscore: `_del`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `erase`
[INFO] [stdout]    --> src/main.rs:191:8
[INFO] [stdout]     |
[INFO] [stdout] 191 |     fn erase() {}
[INFO] [stdout]     |        ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `node_Rc` should have a snake case name
[INFO] [stdout]   --> src/main.rs:24:26
[INFO] [stdout]    |
[INFO] [stdout] 24 |                     Some(node_Rc) => Some(Rc::clone(&node_Rc)),
[INFO] [stdout]    |                          ^^^^^^^ help: convert the identifier to snake case: `node_rc`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.54s
[INFO] running `Command { std: "docker" "inspect" "a3a959ef49bd863ef86bcac6e54584abba91acc0dfe6adfeefb9cffebb746513", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a3a959ef49bd863ef86bcac6e54584abba91acc0dfe6adfeefb9cffebb746513", kill_on_drop: false }`
[INFO] [stdout] a3a959ef49bd863ef86bcac6e54584abba91acc0dfe6adfeefb9cffebb746513
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/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=forbid" "-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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e8397a04204aaf8b9f284182a6f9e27a3c2e67044d0943b4415b160bfc957681" "/opt/rustwide/cargo-home/bin/cargo" "+62efba8a050c64249dab942951bb28f710208bc8" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ecdf4b175d85c037142da3075c9fff7d2ee3059bb62e1d0ec7de32dd3e9e8c93
[INFO] running `Command { std: "docker" "start" "-a" "ecdf4b175d85c037142da3075c9fff7d2ee3059bb62e1d0ec7de32dd3e9e8c93", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling double_linked_list v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `tmp` is never read
[INFO] [stdout]    --> src/main.rs:236:13
[INFO] [stdout]     |
[INFO] [stdout] 236 |     let mut tmp = None;
[INFO] [stdout]     |             ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `tmp2` is never read
[INFO] [stdout]    --> src/main.rs:237:13
[INFO] [stdout]     |
[INFO] [stdout] 237 |     let mut tmp2 = None;
[INFO] [stdout]     |             ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `tmp3` is never read
[INFO] [stdout]    --> src/main.rs:238:13
[INFO] [stdout]     |
[INFO] [stdout] 238 |     let mut tmp3 = None;
[INFO] [stdout]     |             ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `del`
[INFO] [stdout]   --> src/main.rs:86:21
[INFO] [stdout]    |
[INFO] [stdout] 86 |                 let del = node.borrow_mut().next.take();
[INFO] [stdout]    |                     ^^^ help: if this is intentional, prefix it with an underscore: `_del`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `erase`
[INFO] [stdout]    --> src/main.rs:191:8
[INFO] [stdout]     |
[INFO] [stdout] 191 |     fn erase() {}
[INFO] [stdout]     |        ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `node_Rc` should have a snake case name
[INFO] [stdout]   --> src/main.rs:24:26
[INFO] [stdout]    |
[INFO] [stdout] 24 |                     Some(node_Rc) => Some(Rc::clone(&node_Rc)),
[INFO] [stdout]    |                          ^^^^^^^ help: convert the identifier to snake case: `node_rc`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1.11s
[INFO] running `Command { std: "docker" "inspect" "ecdf4b175d85c037142da3075c9fff7d2ee3059bb62e1d0ec7de32dd3e9e8c93", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ecdf4b175d85c037142da3075c9fff7d2ee3059bb62e1d0ec7de32dd3e9e8c93", kill_on_drop: false }`
[INFO] [stdout] ecdf4b175d85c037142da3075c9fff7d2ee3059bb62e1d0ec7de32dd3e9e8c93
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/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=forbid" "-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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e8397a04204aaf8b9f284182a6f9e27a3c2e67044d0943b4415b160bfc957681" "/opt/rustwide/cargo-home/bin/cargo" "+62efba8a050c64249dab942951bb28f710208bc8" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 069d7c570b4e019bbc06e6624f2dc639d2d1e0261ba659b78bee2465b297f2d0
[INFO] running `Command { std: "docker" "start" "-a" "069d7c570b4e019bbc06e6624f2dc639d2d1e0261ba659b78bee2465b297f2d0", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] warning: value assigned to `tmp` is never read
[INFO] [stderr]    --> src/main.rs:236:13
[INFO] [stderr]     |
[INFO] [stderr] 236 |     let mut tmp = None;
[INFO] [stderr]     |             ^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stderr]     = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: value assigned to `tmp2` is never read
[INFO] [stderr]    --> src/main.rs:237:13
[INFO] [stderr]     |
[INFO] [stderr] 237 |     let mut tmp2 = None;
[INFO] [stderr]     |             ^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: value assigned to `tmp3` is never read
[INFO] [stderr]    --> src/main.rs:238:13
[INFO] [stderr]     |
[INFO] [stderr] 238 |     let mut tmp3 = None;
[INFO] [stderr]     |             ^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `del`
[INFO] [stderr]   --> src/main.rs:86:21
[INFO] [stderr]    |
[INFO] [stderr] 86 |                 let del = node.borrow_mut().next.take();
[INFO] [stderr]    |                     ^^^ help: if this is intentional, prefix it with an underscore: `_del`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `erase`
[INFO] [stderr]    --> src/main.rs:191:8
[INFO] [stderr]     |
[INFO] [stderr] 191 |     fn erase() {}
[INFO] [stderr]     |        ^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable `node_Rc` should have a snake case name
[INFO] [stderr]   --> src/main.rs:24:26
[INFO] [stderr]    |
[INFO] [stderr] 24 |                     Some(node_Rc) => Some(Rc::clone(&node_Rc)),
[INFO] [stderr]    |                          ^^^^^^^ help: convert the identifier to snake case: `node_rc`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: `double_linked_list` (bin "double_linked_list" test) generated 6 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.06s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/double_linked_list-213ace4959daf038)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "069d7c570b4e019bbc06e6624f2dc639d2d1e0261ba659b78bee2465b297f2d0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "069d7c570b4e019bbc06e6624f2dc639d2d1e0261ba659b78bee2465b297f2d0", kill_on_drop: false }`
[INFO] [stdout] 069d7c570b4e019bbc06e6624f2dc639d2d1e0261ba659b78bee2465b297f2d0