[INFO] fetching crate io-read-line-prototype 1.0.1...
[INFO] testing io-read-line-prototype-1.0.1 against 1.60.0 for beta-1.61-1
[INFO] extracting crate io-read-line-prototype 1.0.1 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate io-read-line-prototype 1.0.1 on toolchain 1.60.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate io-read-line-prototype 1.0.1
[INFO] finished tweaking crates.io crate io-read-line-prototype 1.0.1
[INFO] tweaked toml for crates.io crate io-read-line-prototype 1.0.1 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "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] dd2d7cdbf0d70c161621a00abcb79ce2a8c1d6c66e7857e011859e34cc2c7ddb
[INFO] running `Command { std: "docker" "start" "-a" "dd2d7cdbf0d70c161621a00abcb79ce2a8c1d6c66e7857e011859e34cc2c7ddb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "dd2d7cdbf0d70c161621a00abcb79ce2a8c1d6c66e7857e011859e34cc2c7ddb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dd2d7cdbf0d70c161621a00abcb79ce2a8c1d6c66e7857e011859e34cc2c7ddb", kill_on_drop: false }`
[INFO] [stdout] dd2d7cdbf0d70c161621a00abcb79ce2a8c1d6c66e7857e011859e34cc2c7ddb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "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:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "build" "--frozen" "--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] f59ab4ff324690fe4618a9df8f27f30c486ca5694088ba09d4aeb8dc6ef5a6eb
[INFO] running `Command { std: "docker" "start" "-a" "f59ab4ff324690fe4618a9df8f27f30c486ca5694088ba09d4aeb8dc6ef5a6eb", kill_on_drop: false }`
[INFO] [stderr]    Compiling io-read-line-prototype v1.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:33:1
[INFO] [stdout]    |
[INFO] [stdout] 33 | #![feature(min_specialization)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `io-read-line-prototype` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "f59ab4ff324690fe4618a9df8f27f30c486ca5694088ba09d4aeb8dc6ef5a6eb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f59ab4ff324690fe4618a9df8f27f30c486ca5694088ba09d4aeb8dc6ef5a6eb", kill_on_drop: false }`
[INFO] [stdout] f59ab4ff324690fe4618a9df8f27f30c486ca5694088ba09d4aeb8dc6ef5a6eb