[INFO] cloning repository https://github.com/sazalo101/rust_exam
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/sazalo101/rust_exam" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsazalo101%2Frust_exam", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsazalo101%2Frust_exam'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0933c4a7d5795be457f84638185bf8aa470715a1
[INFO] checking sazalo101/rust_exam against try#73ffebff6f34db7eb167bf9edcf2afa19c3073e9 for pr-147841
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsazalo101%2Frust_exam" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/sazalo101/rust_exam
[INFO] finished tweaking git repo https://github.com/sazalo101/rust_exam
[INFO] tweaked toml for git repo https://github.com/sazalo101/rust_exam written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/sazalo101/rust_exam on toolchain 73ffebff6f34db7eb167bf9edcf2afa19c3073e9
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+73ffebff6f34db7eb167bf9edcf2afa19c3073e9" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/sazalo101/rust_exam already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+73ffebff6f34db7eb167bf9edcf2afa19c3073e9" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded ic-stable-structures v0.6.7
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+73ffebff6f34db7eb167bf9edcf2afa19c3073e9" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f8ce72847551c9df842928cd45175c19d087d1b8fc37bfb152fafca69d4693b6
[INFO] running `Command { std: "docker" "start" "-a" "f8ce72847551c9df842928cd45175c19d087d1b8fc37bfb152fafca69d4693b6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f8ce72847551c9df842928cd45175c19d087d1b8fc37bfb152fafca69d4693b6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f8ce72847551c9df842928cd45175c19d087d1b8fc37bfb152fafca69d4693b6", kill_on_drop: false }`
[INFO] [stdout] f8ce72847551c9df842928cd45175c19d087d1b8fc37bfb152fafca69d4693b6
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+73ffebff6f34db7eb167bf9edcf2afa19c3073e9" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9f8278ecd27d3f23823d6468ab38760ec3fc1d3d898dc34fab12a7ca82c1a060
[INFO] running `Command { std: "docker" "start" "-a" "9f8278ecd27d3f23823d6468ab38760ec3fc1d3d898dc34fab12a7ca82c1a060", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde_json v1.0.138
[INFO] [stderr]     Checking ic-stable-structures v0.6.7
[INFO] [stderr]     Checking exam_backend v0.1.0 (/opt/rustwide/workdir/src/exam_backend)
[INFO] [stdout] warning: unused import: `cell::Cell`
[INFO] [stdout]  --> src/exam_backend/src/lib.rs:3:28
[INFO] [stdout]   |
[INFO] [stdout] 3 | use ic_stable_structures::{cell::Cell, DefaultMemoryImpl, StableBTreeMap, Storable};
[INFO] [stdout]   |                            ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `cell::Cell`
[INFO] [stdout]  --> src/exam_backend/src/lib.rs:3:28
[INFO] [stdout]   |
[INFO] [stdout] 3 | use ic_stable_structures::{cell::Cell, DefaultMemoryImpl, StableBTreeMap, Storable};
[INFO] [stdout]   |                            ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/exam_backend/src/lib.rs:17:17
[INFO] [stdout]    |
[INFO] [stdout] 17 |     fn to_bytes(&self) -> std::borrow::Cow<[u8]> {
[INFO] [stdout]    |                 ^^^^^     ^^^^^^^^^^^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                 |
[INFO] [stdout]    |                 the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 17 |     fn to_bytes(&self) -> std::borrow::Cow<'_, [u8]> {
[INFO] [stdout]    |                                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/exam_backend/src/lib.rs:17:17
[INFO] [stdout]    |
[INFO] [stdout] 17 |     fn to_bytes(&self) -> std::borrow::Cow<[u8]> {
[INFO] [stdout]    |                 ^^^^^     ^^^^^^^^^^^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                 |
[INFO] [stdout]    |                 the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 17 |     fn to_bytes(&self) -> std::borrow::Cow<'_, [u8]> {
[INFO] [stdout]    |                                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.71s
[INFO] running `Command { std: "docker" "inspect" "9f8278ecd27d3f23823d6468ab38760ec3fc1d3d898dc34fab12a7ca82c1a060", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9f8278ecd27d3f23823d6468ab38760ec3fc1d3d898dc34fab12a7ca82c1a060", kill_on_drop: false }`
[INFO] [stdout] 9f8278ecd27d3f23823d6468ab38760ec3fc1d3d898dc34fab12a7ca82c1a060