[INFO] fetching crate sequencetree 0.1.4...
[INFO] checking sequencetree-0.1.4 against try#901e6d56697c79b2e80df6a487b2318ec6f57ee3 for pr-142287
[INFO] extracting crate sequencetree 0.1.4 into /workspace/builds/worker-5-tc2/source
[INFO] validating manifest of crates.io crate sequencetree 0.1.4 on toolchain 901e6d56697c79b2e80df6a487b2318ec6f57ee3
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+901e6d56697c79b2e80df6a487b2318ec6f57ee3" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate sequencetree 0.1.4
[INFO] finished tweaking crates.io crate sequencetree 0.1.4
[INFO] tweaked toml for crates.io crate sequencetree 0.1.4 written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+901e6d56697c79b2e80df6a487b2318ec6f57ee3" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 15 packages to latest compatible versions
[INFO] [stderr]       Adding rand v0.7.3 (available: v0.9.1)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+901e6d56697c79b2e80df6a487b2318ec6f57ee3" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr] `license` should be used if the package license can be expressed with a standard SPDX expression.
[INFO] [stderr] `license-file` should be used if the package uses a non-standard license.
[INFO] [stderr] See https://doc.rust-lang.org/cargo/reference/manifest.html#the-license-and-license-file-fields for more information.
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/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:eea15d5475069c3ef791f10c2c6b5af2ee421ef2da1e680ecce1cba46243983b" "/opt/rustwide/cargo-home/bin/cargo" "+901e6d56697c79b2e80df6a487b2318ec6f57ee3" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 82c0af8de564f2addfb19c90e9ebe2b88e80f5948eb0c5b5cbd8d94769862222
[INFO] running `Command { std: "docker" "start" "-a" "82c0af8de564f2addfb19c90e9ebe2b88e80f5948eb0c5b5cbd8d94769862222", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "82c0af8de564f2addfb19c90e9ebe2b88e80f5948eb0c5b5cbd8d94769862222", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "82c0af8de564f2addfb19c90e9ebe2b88e80f5948eb0c5b5cbd8d94769862222", kill_on_drop: false }`
[INFO] [stdout] 82c0af8de564f2addfb19c90e9ebe2b88e80f5948eb0c5b5cbd8d94769862222
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/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" "RUSTDOCFLAGS=--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:eea15d5475069c3ef791f10c2c6b5af2ee421ef2da1e680ecce1cba46243983b" "/opt/rustwide/cargo-home/bin/cargo" "+901e6d56697c79b2e80df6a487b2318ec6f57ee3" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e5eaf42f639060f15efbb1c931133cf5e4dc39283a8b4e5d48b5c5e5723c2f86
[INFO] running `Command { std: "docker" "start" "-a" "e5eaf42f639060f15efbb1c931133cf5e4dc39283a8b4e5d48b5c5e5723c2f86", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr] `license` should be used if the package license can be expressed with a standard SPDX expression.
[INFO] [stderr] `license-file` should be used if the package uses a non-standard license.
[INFO] [stderr] See https://doc.rust-lang.org/cargo/reference/manifest.html#the-license-and-license-file-fields for more information.
[INFO] [stderr]    Compiling libc v0.2.172
[INFO] [stderr]     Checking sequencetree v0.1.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::fmt::Debug`
[INFO] [stdout]  --> src/binarysearchtree.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::fmt::Debug;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/binarysearchtree.rs:81:9
[INFO] [stdout]    |
[INFO] [stdout] 81 |     let mut val = match &mut n.val {
[INFO] [stdout]    |         ----^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/binarysearchtree.rs:104:9
[INFO] [stdout]     |
[INFO] [stdout] 104 |     let mut val = match &mut n.val {
[INFO] [stdout]     |         ----^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/sequencetree.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |     let mut n = create_node(key, i, val);
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0515]: cannot return value referencing temporary value
[INFO] [stdout]   --> src/sequencetree.rs:69:5
[INFO] [stdout]    |
[INFO] [stdout] 69 | /     match node.next.search( key[i].to_owned() ) {
[INFO] [stdout] 70 | |         Some(n) => {
[INFO] [stdout] 71 | |             if i == key.len() - 1 {
[INFO] [stdout] 72 | |                 return &n.value;
[INFO] [stdout] ...  |
[INFO] [stdout] 78 | |         None => &None
[INFO] [stdout]    | |                  ---- temporary value created here
[INFO] [stdout] 79 | |     }
[INFO] [stdout]    | |_____^ returns a value referencing data owned by the current function
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0515`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `sequencetree` (lib) due to 1 previous error; 4 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "e5eaf42f639060f15efbb1c931133cf5e4dc39283a8b4e5d48b5c5e5723c2f86", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e5eaf42f639060f15efbb1c931133cf5e4dc39283a8b4e5d48b5c5e5723c2f86", kill_on_drop: false }`
[INFO] [stdout] e5eaf42f639060f15efbb1c931133cf5e4dc39283a8b4e5d48b5c5e5723c2f86