[INFO] fetching crate nexum 0.2.0...
[INFO] checking nexum-0.2.0 against try#901e6d56697c79b2e80df6a487b2318ec6f57ee3 for pr-142287
[INFO] extracting crate nexum 0.2.0 into /workspace/builds/worker-1-tc2/source
[INFO] validating manifest of crates.io crate nexum 0.2.0 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 nexum 0.2.0
[INFO] finished tweaking crates.io crate nexum 0.2.0
[INFO] tweaked toml for crates.io crate nexum 0.2.0 written to /workspace/builds/worker-1-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] 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 5bfe569f53813c98833b04df31a367d881c51f0f6b06407c124e8d6d03493a34
[INFO] running `Command { std: "docker" "start" "-a" "5bfe569f53813c98833b04df31a367d881c51f0f6b06407c124e8d6d03493a34", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5bfe569f53813c98833b04df31a367d881c51f0f6b06407c124e8d6d03493a34", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5bfe569f53813c98833b04df31a367d881c51f0f6b06407c124e8d6d03493a34", kill_on_drop: false }`
[INFO] [stdout] 5bfe569f53813c98833b04df31a367d881c51f0f6b06407c124e8d6d03493a34
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 26f4999345312215009028abf769912820d1355ef97ca786fd77293dbb894430
[INFO] running `Command { std: "docker" "start" "-a" "26f4999345312215009028abf769912820d1355ef97ca786fd77293dbb894430", kill_on_drop: false }`
[INFO] [stderr]     Checking nexum v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0515]: cannot return reference to temporary value
[INFO] [stdout]   --> src/auto_expand_vector/vector.rs:51:20
[INFO] [stdout]    |
[INFO] [stdout] 51 |             return &None;
[INFO] [stdout]    |                    ^----
[INFO] [stdout]    |                    ||
[INFO] [stdout]    |                    |temporary value created here
[INFO] [stdout]    |                    returns a reference to data owned by the current function
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0515]: cannot return reference to temporary value
[INFO] [stdout]   --> src/auto_expand_vector/vector.rs:51:20
[INFO] [stdout]    |
[INFO] [stdout] 51 |             return &None;
[INFO] [stdout]    |                    ^----
[INFO] [stdout]    |                    ||
[INFO] [stdout]    |                    |temporary value created here
[INFO] [stdout]    |                    returns a reference to 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 `nexum` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] For more information about this error, try `rustc --explain E0515`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `nexum` (lib test) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "26f4999345312215009028abf769912820d1355ef97ca786fd77293dbb894430", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "26f4999345312215009028abf769912820d1355ef97ca786fd77293dbb894430", kill_on_drop: false }`
[INFO] [stdout] 26f4999345312215009028abf769912820d1355ef97ca786fd77293dbb894430