[INFO] fetching crate kakao-rs 0.2.4...
[INFO] testing kakao-rs-0.2.4 against 1.54.0 for beta-1.55-1
[INFO] extracting crate kakao-rs 0.2.4 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate kakao-rs 0.2.4 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate kakao-rs 0.2.4
[INFO] removed 0 missing examples
[INFO] finished tweaking crates.io crate kakao-rs 0.2.4
[INFO] tweaked toml for crates.io crate kakao-rs 0.2.4 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate crates.io crate kakao-rs 0.2.4 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cb6e608501e2a9dafe7ac3c21ad7ae7bec071383fa28778bcbd7060695be0854
[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" "cb6e608501e2a9dafe7ac3c21ad7ae7bec071383fa28778bcbd7060695be0854", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cb6e608501e2a9dafe7ac3c21ad7ae7bec071383fa28778bcbd7060695be0854", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cb6e608501e2a9dafe7ac3c21ad7ae7bec071383fa28778bcbd7060695be0854", kill_on_drop: false }`
[INFO] [stdout] cb6e608501e2a9dafe7ac3c21ad7ae7bec071383fa28778bcbd7060695be0854
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a04bf9a6cdf3e29361de0f358f8d405a6d4df45d6e233a22b79ec502c9a4ac70
[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" "a04bf9a6cdf3e29361de0f358f8d405a6d4df45d6e233a22b79ec502c9a4ac70", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde_json v1.0.65
[INFO] [stderr]    Compiling serde_derive v1.0.126
[INFO] [stderr]    Compiling serde v1.0.126
[INFO] [stderr]    Compiling kakao-rs v0.2.4 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:41:1
[INFO] [stdout]    |
[INFO] [stdout] 41 | #![feature(proc_macro_hygiene, decl_macro)]
[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 `kakao-rs`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "a04bf9a6cdf3e29361de0f358f8d405a6d4df45d6e233a22b79ec502c9a4ac70", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a04bf9a6cdf3e29361de0f358f8d405a6d4df45d6e233a22b79ec502c9a4ac70", kill_on_drop: false }`
[INFO] [stdout] a04bf9a6cdf3e29361de0f358f8d405a6d4df45d6e233a22b79ec502c9a4ac70
