[INFO] fetching crate notes 0.2.108...
[INFO] testing notes-0.2.108 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate notes 0.2.108 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate notes 0.2.108 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 crates.io crate notes 0.2.108
[INFO] finished tweaking crates.io crate notes 0.2.108
[INFO] tweaked toml for crates.io crate notes 0.2.108 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate crates.io crate notes 0.2.108 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]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2e5017aec9e9707ca71fd25f20ad77beff017503d6ad402cf8a190698056d0f1
[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" "2e5017aec9e9707ca71fd25f20ad77beff017503d6ad402cf8a190698056d0f1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2e5017aec9e9707ca71fd25f20ad77beff017503d6ad402cf8a190698056d0f1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2e5017aec9e9707ca71fd25f20ad77beff017503d6ad402cf8a190698056d0f1", kill_on_drop: false }`
[INFO] [stdout] 2e5017aec9e9707ca71fd25f20ad77beff017503d6ad402cf8a190698056d0f1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 36ec3e5f96bbf188a651a8c9c9be98b605eb84ac1cfc1f85d4b1e11f1d7b51fc
[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" "36ec3e5f96bbf188a651a8c9c9be98b605eb84ac1cfc1f85d4b1e11f1d7b51fc", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.76
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling ppv-lite86 v0.2.9
[INFO] [stderr]    Compiling serde v1.0.115
[INFO] [stderr]    Compiling unicode-width v0.1.8
[INFO] [stderr]    Compiling same-file v1.0.6
[INFO] [stderr]    Compiling regex-syntax v0.6.18
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling thread_local v1.0.1
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling walkdir v2.3.1
[INFO] [stderr]    Compiling aho-corasick v0.7.13
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling dirs-sys v0.3.5
[INFO] [stderr]    Compiling time v0.1.43
[INFO] [stderr]    Compiling colored v1.9.3
[INFO] [stderr]    Compiling clap v2.33.3
[INFO] [stderr]    Compiling dirs v2.0.2
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.2
[INFO] [stderr]    Compiling chrono v0.4.15
[INFO] [stderr]    Compiling rand v0.7.3
[INFO] [stderr]    Compiling regex v1.3.9
[INFO] [stderr]    Compiling uuid v0.8.1
[INFO] [stderr]    Compiling notes v0.2.108 (/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(backtrace)]
[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 `notes`
[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 `Command { std: "docker" "inspect" "36ec3e5f96bbf188a651a8c9c9be98b605eb84ac1cfc1f85d4b1e11f1d7b51fc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "36ec3e5f96bbf188a651a8c9c9be98b605eb84ac1cfc1f85d4b1e11f1d7b51fc", kill_on_drop: false }`
[INFO] [stdout] 36ec3e5f96bbf188a651a8c9c9be98b605eb84ac1cfc1f85d4b1e11f1d7b51fc