[INFO] cloning repository https://github.com/elferherrera/test_example
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/elferherrera/test_example" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Felferherrera%2Ftest_example", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Felferherrera%2Ftest_example'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 71fa56baf1f6da517dfaa2d591cb86625891bd92
[INFO] testing elferherrera/test_example against beta-2021-01-01 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Felferherrera%2Ftest_example" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/elferherrera/test_example on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/elferherrera/test_example
[INFO] finished tweaking git repo https://github.com/elferherrera/test_example
[INFO] tweaked toml for git repo https://github.com/elferherrera/test_example written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/elferherrera/test_example already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded flatbuffers v0.6.1
[INFO] [stderr]   Downloaded num-bigint v0.3.0
[INFO] [stderr]   Downloaded arrow v1.0.1
[INFO] [stderr]   Downloaded num v0.3.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cc5cb9df7858a873b79a8102d216f4afcb20177d7bdd94b9c5af81c77fc64344
[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" "cc5cb9df7858a873b79a8102d216f4afcb20177d7bdd94b9c5af81c77fc64344", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cc5cb9df7858a873b79a8102d216f4afcb20177d7bdd94b9c5af81c77fc64344", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cc5cb9df7858a873b79a8102d216f4afcb20177d7bdd94b9c5af81c77fc64344", kill_on_drop: false }`
[INFO] [stdout] cc5cb9df7858a873b79a8102d216f4afcb20177d7bdd94b9c5af81c77fc64344
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 54a556e81395f5e1878eda4f38ddfe0e3179665dc8f42c9a1bce3c4593f16c0f
[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" "54a556e81395f5e1878eda4f38ddfe0e3179665dc8f42c9a1bce3c4593f16c0f", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.117
[INFO] [stderr]    Compiling syn v1.0.44
[INFO] [stderr]    Compiling serde_json v1.0.59
[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-rational v0.3.0
[INFO] [stderr]    Compiling num-iter v0.1.41
[INFO] [stderr]    Compiling flatbuffers v0.6.1
[INFO] [stderr]    Compiling csv-core v0.1.10
[INFO] [stderr]    Compiling num-complex v0.3.0
[INFO] [stderr]    Compiling chrono v0.4.19
[INFO] [stderr]    Compiling num v0.3.0
[INFO] [stderr]    Compiling serde_derive v1.0.117
[INFO] [stderr]    Compiling bstr v0.2.13
[INFO] [stderr]    Compiling csv v1.1.3
[INFO] [stderr]    Compiling arrow v1.0.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/arrow-1.0.1/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" "54a556e81395f5e1878eda4f38ddfe0e3179665dc8f42c9a1bce3c4593f16c0f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "54a556e81395f5e1878eda4f38ddfe0e3179665dc8f42c9a1bce3c4593f16c0f", kill_on_drop: false }`
[INFO] [stdout] 54a556e81395f5e1878eda4f38ddfe0e3179665dc8f42c9a1bce3c4593f16c0f