[INFO] cloning repository https://github.com/tawashichan/untyped_lambda_calculus
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tawashichan/untyped_lambda_calculus" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftawashichan%2Funtyped_lambda_calculus"`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftawashichan%2Funtyped_lambda_calculus'...
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 36470b89855464df2e4dbc53f58501fb55188d98
[INFO] testing tawashichan/untyped_lambda_calculus against 1.44.0 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftawashichan%2Funtyped_lambda_calculus" "/workspace/builds/worker-9/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tawashichan/untyped_lambda_calculus on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/tawashichan/untyped_lambda_calculus
[INFO] finished tweaking git repo https://github.com/tawashichan/untyped_lambda_calculus
[INFO] tweaked toml for git repo https://github.com/tawashichan/untyped_lambda_calculus written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/tawashichan/untyped_lambda_calculus already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] ea58820e0d5a0a275c66d16d067f72cbe16b07e2f866934d77127a5487934f6e
[INFO] running `"docker" "start" "-a" "ea58820e0d5a0a275c66d16d067f72cbe16b07e2f866934d77127a5487934f6e"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]    Compiling nanoid v0.1.3
[INFO] [stderr]    Compiling untyped_lambda v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(slice_patterns)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | #![feature(box_syntax, box_patterns)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:4:1
[INFO] [stderr]   |
[INFO] [stderr] 4 | #![feature(vec_remove_item)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 3 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `untyped_lambda`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "ea58820e0d5a0a275c66d16d067f72cbe16b07e2f866934d77127a5487934f6e"`
[INFO] running `"docker" "rm" "-f" "ea58820e0d5a0a275c66d16d067f72cbe16b07e2f866934d77127a5487934f6e"`
[INFO] [stdout] ea58820e0d5a0a275c66d16d067f72cbe16b07e2f866934d77127a5487934f6e