[INFO] fetching crate byml 0.1.4...
[INFO] testing byml-0.1.4 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate byml 0.1.4 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate byml 0.1.4 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 byml 0.1.4
[INFO] finished tweaking crates.io crate byml 0.1.4
[INFO] tweaked toml for crates.io crate byml 0.1.4 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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 binread_derive v1.4.2
[INFO] [stderr]   Downloaded binread v1.4.1
[INFO] [stderr]   Downloaded binwrite v0.2.1
[INFO] [stderr]   Downloaded cached_proc_macro v0.4.0
[INFO] [stderr]   Downloaded binwrite_derive v0.2.1
[INFO] [stderr]   Downloaded yaz0 v0.1.2
[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" "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] ce18aabdc252085ae8144f9476c768ec62aabfeaab3de3ad06de3cab9c2d9b55
[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" "ce18aabdc252085ae8144f9476c768ec62aabfeaab3de3ad06de3cab9c2d9b55", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ce18aabdc252085ae8144f9476c768ec62aabfeaab3de3ad06de3cab9c2d9b55", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ce18aabdc252085ae8144f9476c768ec62aabfeaab3de3ad06de3cab9c2d9b55", kill_on_drop: false }`
[INFO] [stdout] ce18aabdc252085ae8144f9476c768ec62aabfeaab3de3ad06de3cab9c2d9b55
[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" "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] df662298c6c0245e94d8ab1c4c047d16b5aeb121bc972d4ab3a826fdce140769
[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" "df662298c6c0245e94d8ab1c4c047d16b5aeb121bc972d4ab3a826fdce140769", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.57
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]    Compiling indexmap v1.6.1
[INFO] [stderr]    Compiling paste-impl v0.1.18
[INFO] [stderr]    Compiling parse_int v0.4.0
[INFO] [stderr]    Compiling paste v0.1.18
[INFO] [stderr]    Compiling yaz0 v0.1.2
[INFO] [stderr]    Compiling darling_core v0.10.2
[INFO] [stderr]    Compiling pin-project-internal v1.0.2
[INFO] [stderr]    Compiling futures-macro v0.3.8
[INFO] [stderr]    Compiling binread_derive v1.4.2
[INFO] [stderr]    Compiling async-trait v0.1.42
[INFO] [stderr]    Compiling binwrite_derive v0.2.1
[INFO] [stderr]    Compiling thiserror-impl v1.0.23
[INFO] [stderr]    Compiling darling_macro v0.10.2
[INFO] [stderr]    Compiling binwrite v0.2.1
[INFO] [stderr]    Compiling thiserror v1.0.23
[INFO] [stderr]    Compiling pin-project v1.0.2
[INFO] [stderr]    Compiling futures-util v0.3.8
[INFO] [stderr]    Compiling darling v0.10.2
[INFO] [stderr]    Compiling cached_proc_macro v0.4.0
[INFO] [stderr]    Compiling binread v1.4.1
[INFO] [stderr]    Compiling futures-executor v0.3.8
[INFO] [stderr]    Compiling futures v0.3.8
[INFO] [stderr]    Compiling cached v0.20.0
[INFO] [stderr]    Compiling byml v0.1.4 (/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(seek_convenience)]
[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 `byml`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "df662298c6c0245e94d8ab1c4c047d16b5aeb121bc972d4ab3a826fdce140769", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "df662298c6c0245e94d8ab1c4c047d16b5aeb121bc972d4ab3a826fdce140769", kill_on_drop: false }`
[INFO] [stdout] df662298c6c0245e94d8ab1c4c047d16b5aeb121bc972d4ab3a826fdce140769