[INFO] fetching crate polars 0.2.1...
[INFO] testing polars-0.2.1 against 1.45.2 for beta-1.46-1
[INFO] extracting crate polars 0.2.1 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate polars 0.2.1 on toolchain 1.45.2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate polars 0.2.1
[INFO] finished tweaking crates.io crate polars 0.2.1
[INFO] tweaked toml for crates.io crate polars 0.2.1 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "fetch" "--locked" "--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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f0406ed138d7573af56b449a5f83fd75e2a069bf6c5877b3209576dbc3681cbf
[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" "f0406ed138d7573af56b449a5f83fd75e2a069bf6c5877b3209576dbc3681cbf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f0406ed138d7573af56b449a5f83fd75e2a069bf6c5877b3209576dbc3681cbf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f0406ed138d7573af56b449a5f83fd75e2a069bf6c5877b3209576dbc3681cbf", kill_on_drop: false }`
[INFO] [stdout] f0406ed138d7573af56b449a5f83fd75e2a069bf6c5877b3209576dbc3681cbf
[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" "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@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "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] 316be95730f9124c95ff80d1f6e42c9b11d363103feed126af7503b1dd15e6b8
[INFO] running `Command { std: "docker" "start" "-a" "316be95730f9124c95ff80d1f6e42c9b11d363103feed126af7503b1dd15e6b8", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling serde v1.0.114
[INFO] [stderr]    Compiling itoa v0.4.6
[INFO] [stderr]    Compiling serde_json v1.0.57
[INFO] [stderr]    Compiling regex-syntax v0.6.18
[INFO] [stderr]    Compiling smallvec v1.4.1
[INFO] [stderr]    Compiling encode_unicode v0.3.6
[INFO] [stderr]    Compiling hex v0.4.2
[INFO] [stderr]    Compiling unsafe_unwrap v0.1.0
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling num-bigint v0.3.0
[INFO] [stderr]    Compiling num-iter v0.1.41
[INFO] [stderr]    Compiling hashbrown v0.8.1
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling num-rational v0.3.0
[INFO] [stderr]    Compiling indexmap v1.5.0
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling thread_local v1.0.1
[INFO] [stderr]    Compiling itertools v0.9.0
[INFO] [stderr]    Compiling flatbuffers v0.6.1
[INFO] [stderr]    Compiling regex-automata v0.1.9
[INFO] [stderr]    Compiling dirs v1.0.5
[INFO] [stderr]    Compiling thiserror-impl v1.0.20
[INFO] [stderr]    Compiling crossbeam v0.7.3
[INFO] [stderr]    Compiling term v0.5.2
[INFO] [stderr]    Compiling csv-core v0.1.10
[INFO] [stderr]    Compiling aho-corasick v0.7.13
[INFO] [stderr]    Compiling prettytable-rs v0.8.0
[INFO] [stderr]    Compiling num-complex v0.3.0
[INFO] [stderr]    Compiling thiserror v1.0.20
[INFO] [stderr]    Compiling chrono v0.4.13
[INFO] [stderr]    Compiling regex v1.3.9
[INFO] [stderr]    Compiling num v0.2.1
[INFO] [stderr]    Compiling num v0.3.0
[INFO] [stderr]    Compiling bstr v0.2.13
[INFO] [stderr]    Compiling csv v1.1.3
[INFO] [stderr]    Compiling arrow v1.0.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/arrow-1.0.0/src/lib.rs:24:1
[INFO] [stdout]    |
[INFO] [stdout] 24 | #![feature(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 `arrow`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "316be95730f9124c95ff80d1f6e42c9b11d363103feed126af7503b1dd15e6b8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "316be95730f9124c95ff80d1f6e42c9b11d363103feed126af7503b1dd15e6b8", kill_on_drop: false }`
[INFO] [stdout] 316be95730f9124c95ff80d1f6e42c9b11d363103feed126af7503b1dd15e6b8