[INFO] cloning repository https://github.com/Renmusxd/IsingMonteCarlo
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Renmusxd/IsingMonteCarlo" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRenmusxd%2FIsingMonteCarlo"`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRenmusxd%2FIsingMonteCarlo'...
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] e8e5ce3b34ef248ad3b1147a663276ad881b0565
[INFO] testing Renmusxd/IsingMonteCarlo against 1.44.0 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRenmusxd%2FIsingMonteCarlo" "/workspace/builds/worker-7/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Renmusxd/IsingMonteCarlo 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/Renmusxd/IsingMonteCarlo
[INFO] finished tweaking git repo https://github.com/Renmusxd/IsingMonteCarlo
[INFO] tweaked toml for git repo https://github.com/Renmusxd/IsingMonteCarlo written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 705cfa545148adf5c43d3cd0edc10d3d893bcf8daa9feff2eeb3c9c2d33f8b6f
[INFO] running `"docker" "start" "-a" "705cfa545148adf5c43d3cd0edc10d3d893bcf8daa9feff2eeb3c9c2d33f8b6f"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling smallvec v1.4.0
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling num-iter v0.1.40
[INFO] [stderr]    Compiling rand_pcg v0.2.1
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/smallvec-1.4.0/lib.rs:62:41
[INFO] [stderr]    |
[INFO] [stderr] 62 | #![cfg_attr(feature = "specialization", feature(specialization))]
[INFO] [stderr]    |                                         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]    Compiling rand v0.7.3
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `smallvec`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "705cfa545148adf5c43d3cd0edc10d3d893bcf8daa9feff2eeb3c9c2d33f8b6f"`
[INFO] running `"docker" "rm" "-f" "705cfa545148adf5c43d3cd0edc10d3d893bcf8daa9feff2eeb3c9c2d33f8b6f"`
[INFO] [stdout] 705cfa545148adf5c43d3cd0edc10d3d893bcf8daa9feff2eeb3c9c2d33f8b6f