[INFO] cloning repository https://github.com/popey456963/lingo
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/popey456963/lingo" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpopey456963%2Flingo", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpopey456963%2Flingo'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 49682c180974983fd7afeef50784dcca4b9030b2
[INFO] testing popey456963/lingo against 1.60.0 for beta-1.61-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpopey456963%2Flingo" "/workspace/builds/worker-11/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/popey456963/lingo 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] removed /workspace/builds/worker-11/source/.cargo/config.toml
[INFO] started tweaking git repo https://github.com/popey456963/lingo
[INFO] finished tweaking git repo https://github.com/popey456963/lingo
[INFO] tweaked toml for git repo https://github.com/popey456963/lingo written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/popey456963/lingo already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: unused manifest key: unstable
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] [stdout] d3d28721cca4016f8f884d616f834185fa555fdf72d35c3003103f3f326c5b36
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "d3d28721cca4016f8f884d616f834185fa555fdf72d35c3003103f3f326c5b36", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d3d28721cca4016f8f884d616f834185fa555fdf72d35c3003103f3f326c5b36", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d3d28721cca4016f8f884d616f834185fa555fdf72d35c3003103f3f326c5b36", kill_on_drop: false }`
[INFO] [stdout] d3d28721cca4016f8f884d616f834185fa555fdf72d35c3003103f3f326c5b36
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] 5ff044d1d7feeb87c12fde520ff0df8070c304c976af30afca750e7c04eaf466
[INFO] running `Command { std: "docker" "start" "-a" "5ff044d1d7feeb87c12fde520ff0df8070c304c976af30afca750e7c04eaf466", kill_on_drop: false }`
[INFO] [stderr] warning: unused manifest key: unstable
[INFO] [stderr]    Compiling rayon-core v1.9.1
[INFO] [stderr]    Compiling rayon v1.5.1
[INFO] [stderr]    Compiling lingo v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: function is never used: `read_u8_from_stdin`
[INFO] [stdout]   --> src/main.rs:88:4
[INFO] [stdout]    |
[INFO] [stdout] 88 | fn read_u8_from_stdin() -> u8 {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `c`
[INFO] [stdout]    --> src/main.rs:135:4
[INFO] [stdout]     |
[INFO] [stdout] 135 | fn c(a: &str) -> Vec<char> {
[INFO] [stdout]     |    ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(iter_intersperse)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lingo` due to 2 previous errors; 2 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "5ff044d1d7feeb87c12fde520ff0df8070c304c976af30afca750e7c04eaf466", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5ff044d1d7feeb87c12fde520ff0df8070c304c976af30afca750e7c04eaf466", kill_on_drop: false }`
[INFO] [stdout] 5ff044d1d7feeb87c12fde520ff0df8070c304c976af30afca750e7c04eaf466