[INFO] fetching crate rithm 0.1.1...
[INFO] testing rithm-0.1.1 against beta-2021-09-08 for beta-1.56-1
[INFO] extracting crate rithm 0.1.1 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate rithm 0.1.1 on toolchain beta-2021-09-08
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-9/source/rust-toolchain.toml
[INFO] started tweaking crates.io crate rithm 0.1.1
[INFO] finished tweaking crates.io crate rithm 0.1.1
[INFO] tweaked toml for crates.io crate rithm 0.1.1 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "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" "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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c3d1527abb7145dd09028227846aca163ec4ccfe797fe1a70868df0a4c1838ee
[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" "c3d1527abb7145dd09028227846aca163ec4ccfe797fe1a70868df0a4c1838ee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c3d1527abb7145dd09028227846aca163ec4ccfe797fe1a70868df0a4c1838ee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c3d1527abb7145dd09028227846aca163ec4ccfe797fe1a70868df0a4c1838ee", kill_on_drop: false }`
[INFO] [stdout] c3d1527abb7145dd09028227846aca163ec4ccfe797fe1a70868df0a4c1838ee
[INFO] running `Command { std: "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" "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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9292c78eed4649567f88f05fafcb6af0670762f9335b4c9d9990035d659dbb3b
[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" "9292c78eed4649567f88f05fafcb6af0670762f9335b4c9d9990035d659dbb3b", kill_on_drop: false }`
[INFO] [stderr]    Compiling pyo3-build-config v0.14.5
[INFO] [stderr]    Compiling once_cell v1.8.0
[INFO] [stderr]    Compiling scopeguard v1.1.0
[INFO] [stderr]    Compiling unindent v0.1.7
[INFO] [stderr]    Compiling smallvec v1.6.1
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-bigint v0.4.2
[INFO] [stderr]    Compiling num-rational v0.4.0
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling instant v0.1.10
[INFO] [stderr]    Compiling syn v1.0.76
[INFO] [stderr]    Compiling paste v0.1.18
[INFO] [stderr]    Compiling lock_api v0.4.5
[INFO] [stderr]    Compiling parking_lot_core v0.8.5
[INFO] [stderr]    Compiling parking_lot v0.11.2
[INFO] [stderr]    Compiling num-complex v0.4.0
[INFO] [stderr]    Compiling pyo3 v0.14.5
[INFO] [stderr]    Compiling pyo3-macros-backend v0.14.5
[INFO] [stderr]    Compiling num v0.4.0
[INFO] [stderr]    Compiling indoc-impl v0.3.6
[INFO] [stderr]    Compiling pyo3-macros v0.14.5
[INFO] [stderr]    Compiling indoc v0.3.6
[INFO] [stderr]    Compiling rithm v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(destructuring_assignment)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(option_result_unwrap_unchecked)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rithm` due to 3 previous errors
[INFO] running `Command { std: "docker" "inspect" "9292c78eed4649567f88f05fafcb6af0670762f9335b4c9d9990035d659dbb3b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9292c78eed4649567f88f05fafcb6af0670762f9335b4c9d9990035d659dbb3b", kill_on_drop: false }`
[INFO] [stdout] 9292c78eed4649567f88f05fafcb6af0670762f9335b4c9d9990035d659dbb3b