[INFO] fetching crate ys-kcp 1.2.1...
[INFO] testing ys-kcp-1.2.1 against 1.91.0 for beta-1.92-2
[INFO] extracting crate ys-kcp 1.2.1 into /workspace/builds/worker-4-tc1/source
[INFO] started tweaking crates.io crate ys-kcp 1.2.1
[INFO] removed 0 missing tests
[INFO] finished tweaking crates.io crate ys-kcp 1.2.1
[INFO] tweaked toml for crates.io crate ys-kcp 1.2.1 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate ys-kcp 1.2.1 on toolchain 1.91.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate ys-kcp 1.2.1 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" "+1.91.0" "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 xxhash-rust v0.8.10
[INFO] [stderr]   Downloaded const_fn v0.4.10
[INFO] [stderr]   Downloaded addr2line v0.22.0
[INFO] [stderr]   Downloaded sha1_smol v1.0.0
[INFO] [stderr]   Downloaded serde_derive v1.0.201
[INFO] [stderr]   Downloaded serde v1.0.201
[INFO] [stderr]   Downloaded backtrace v0.3.73
[INFO] [stderr]   Downloaded gimli v0.29.0
[INFO] [stderr]   Downloaded libc v0.2.154
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9aa124ba7a9f5b116585688c5de642fbf04bebab37d8bb7dca2982736052b325
[INFO] running `Command { std: "docker" "start" "-a" "9aa124ba7a9f5b116585688c5de642fbf04bebab37d8bb7dca2982736052b325", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9aa124ba7a9f5b116585688c5de642fbf04bebab37d8bb7dca2982736052b325", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9aa124ba7a9f5b116585688c5de642fbf04bebab37d8bb7dca2982736052b325", kill_on_drop: false }`
[INFO] [stdout] 9aa124ba7a9f5b116585688c5de642fbf04bebab37d8bb7dca2982736052b325
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 026fb311284a559cf06371b597e150cde45632ce0a98eb2ec7f7fc51e2dd6423
[INFO] running `Command { std: "docker" "start" "-a" "026fb311284a559cf06371b597e150cde45632ce0a98eb2ec7f7fc51e2dd6423", kill_on_drop: false }`
[INFO] [stderr]    Compiling log v0.4.21
[INFO] [stderr]    Compiling ys-kcp v1.2.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![feature(stmt_expr_attributes)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ys-kcp` (lib) due to 1 previous error
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "026fb311284a559cf06371b597e150cde45632ce0a98eb2ec7f7fc51e2dd6423", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "026fb311284a559cf06371b597e150cde45632ce0a98eb2ec7f7fc51e2dd6423", kill_on_drop: false }`
[INFO] [stdout] 026fb311284a559cf06371b597e150cde45632ce0a98eb2ec7f7fc51e2dd6423