[INFO] fetching crate varint 0.9.0...
[INFO] checking varint-0.9.0 against try#6f8a6450478f69b8510c8976ab6c2a70b3b0e47c for pr-84920
[INFO] extracting crate varint 0.9.0 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate varint 0.9.0 on toolchain 6f8a6450478f69b8510c8976ab6c2a70b3b0e47c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate varint 0.9.0
[INFO] finished tweaking crates.io crate varint 0.9.0
[INFO] tweaked toml for crates.io crate varint 0.9.0 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded bit_utils v0.1.1
[INFO] [stderr]   Downloaded io_operations v0.2.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 49d09d146c04c785146e1c9a41b399dfd02bcc666454d9a78d2ebe88f191a928
[INFO] running `Command { std: "docker" "start" "-a" "49d09d146c04c785146e1c9a41b399dfd02bcc666454d9a78d2ebe88f191a928", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "49d09d146c04c785146e1c9a41b399dfd02bcc666454d9a78d2ebe88f191a928", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "49d09d146c04c785146e1c9a41b399dfd02bcc666454d9a78d2ebe88f191a928", kill_on_drop: false }`
[INFO] [stdout] 49d09d146c04c785146e1c9a41b399dfd02bcc666454d9a78d2ebe88f191a928
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 7dc44f3530d8973050082e601f97b73f689f8a775d09cb58be78782fd41bf617
[INFO] running `Command { std: "docker" "start" "-a" "7dc44f3530d8973050082e601f97b73f689f8a775d09cb58be78782fd41bf617", kill_on_drop: false }`
[INFO] [stderr]     Checking bit_utils v0.1.1
[INFO] [stderr]     Checking varint v0.9.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `next_byte` is never read
[INFO] [stdout]   --> src/rawio.rs:37:17
[INFO] [stdout]    |
[INFO] [stdout] 37 |         let mut next_byte: u8 = 0;
[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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `next_byte` is never read
[INFO] [stdout]   --> src/rawio.rs:37:17
[INFO] [stdout]    |
[INFO] [stdout] 37 |         let mut next_byte: u8 = 0;
[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] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.81s
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "7dc44f3530d8973050082e601f97b73f689f8a775d09cb58be78782fd41bf617", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7dc44f3530d8973050082e601f97b73f689f8a775d09cb58be78782fd41bf617", kill_on_drop: false }`
[INFO] [stdout] 7dc44f3530d8973050082e601f97b73f689f8a775d09cb58be78782fd41bf617