[INFO] fetching crate smart_buffer 0.1.3...
[INFO] testing smart_buffer-0.1.3 against 1.90.0 for beta-1.91-3
[INFO] extracting crate smart_buffer 0.1.3 into /workspace/builds/worker-6-tc1/source
[INFO] started tweaking crates.io crate smart_buffer 0.1.3
[INFO] finished tweaking crates.io crate smart_buffer 0.1.3
[INFO] tweaked toml for crates.io crate smart_buffer 0.1.3 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate smart_buffer 0.1.3 on toolchain 1.90.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "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-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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" "+1.90.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2cfc5baeeed03b78d3be54427cb920a2f3e2b3219eb827f983af534be0e5842e
[INFO] running `Command { std: "docker" "start" "-a" "2cfc5baeeed03b78d3be54427cb920a2f3e2b3219eb827f983af534be0e5842e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2cfc5baeeed03b78d3be54427cb920a2f3e2b3219eb827f983af534be0e5842e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2cfc5baeeed03b78d3be54427cb920a2f3e2b3219eb827f983af534be0e5842e", kill_on_drop: false }`
[INFO] [stdout] 2cfc5baeeed03b78d3be54427cb920a2f3e2b3219eb827f983af534be0e5842e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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" "+1.90.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] aacb3c078763c23e4d41352ce088591893ee986cf823a5bb31f1327d12ab4dab
[INFO] running `Command { std: "docker" "start" "-a" "aacb3c078763c23e4d41352ce088591893ee986cf823a5bb31f1327d12ab4dab", kill_on_drop: false }`
[INFO] [stderr]    Compiling smart_buffer v0.1.3 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(min_const_generics)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `min_const_generics` has been stable since `1.51.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `#[macro_use]` import
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #[macro_use]
[INFO] [stdout]   | ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::iter::SmartBufferIterRef`
[INFO] [stdout]   --> src/lib.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | use crate::iter::SmartBufferIterRef;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `dealloc`
[INFO] [stdout]  --> src/iter.rs:4:20
[INFO] [stdout]   |
[INFO] [stdout] 4 | use alloc::alloc::{dealloc};
[INFO] [stdout]   |                    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
[INFO] [stdout]   --> src/lib.rs:42:1
[INFO] [stdout]    |
[INFO] [stdout] 42 | #[feature(min_const_generics)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_attributes)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `min_const_generics` has been stable since 1.51.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(min_const_generics)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `smart_buffer` (lib) due to 1 previous error; 5 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "aacb3c078763c23e4d41352ce088591893ee986cf823a5bb31f1327d12ab4dab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "aacb3c078763c23e4d41352ce088591893ee986cf823a5bb31f1327d12ab4dab", kill_on_drop: false }`
[INFO] [stdout] aacb3c078763c23e4d41352ce088591893ee986cf823a5bb31f1327d12ab4dab