[INFO] fetching crate cpclib-disc 0.4.2-alpha...
[INFO] documenting cpclib-disc-0.4.2-alpha against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate cpclib-disc 0.4.2-alpha into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate cpclib-disc 0.4.2-alpha on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate cpclib-disc 0.4.2-alpha
[INFO] finished tweaking crates.io crate cpclib-disc 0.4.2-alpha
[INFO] tweaked toml for crates.io crate cpclib-disc 0.4.2-alpha written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate crates.io crate cpclib-disc 0.4.2-alpha already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c504df56e70128a91d5adb19e66bd815011a76634ade9c2a85a5b091b4c644b5
[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" "c504df56e70128a91d5adb19e66bd815011a76634ade9c2a85a5b091b4c644b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c504df56e70128a91d5adb19e66bd815011a76634ade9c2a85a5b091b4c644b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c504df56e70128a91d5adb19e66bd815011a76634ade9c2a85a5b091b4c644b5", kill_on_drop: false }`
[INFO] [stdout] c504df56e70128a91d5adb19e66bd815011a76634ade9c2a85a5b091b4c644b5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "RUSTDOCFLAGS=--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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--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] dbe497b2b52c6e020c8fb397cd3ebc965a07c45946501383a99c86b766063d4c
[INFO] running `Command { std: "docker" "start" "-a" "dbe497b2b52c6e020c8fb397cd3ebc965a07c45946501383a99c86b766063d4c", kill_on_drop: false }`
[INFO] [stderr]    Compiling tinyvec v0.3.3
[INFO] [stderr]    Compiling lexical-core v0.7.4
[INFO] [stderr]     Checking arrayvec v0.5.1
[INFO] [stderr]     Checking static_assertions v1.1.0
[INFO] [stderr]     Checking bitsets v0.1.1
[INFO] [stderr]     Checking strsim v0.9.3
[INFO] [stderr]     Checking bitfield v0.13.2
[INFO] [stderr]     Checking custom_error v1.7.1
[INFO] [stderr]    Compiling nom v5.1.2
[INFO] [stderr]    Compiling paste-impl v0.1.18
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling time v0.1.43
[INFO] [stderr]    Compiling syn v1.0.33
[INFO] [stderr]    Compiling delegate v0.3.0
[INFO] [stderr]    Compiling unicode-normalization v0.1.13
[INFO] [stderr]     Checking paste v0.1.18
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling idna v0.2.0
[INFO] [stderr]    Compiling chrono v0.4.12
[INFO] [stderr]    Compiling url v2.1.1
[INFO] [stderr]    Compiling synstructure v0.12.4
[INFO] [stderr]    Compiling serde_derive v1.0.114
[INFO] [stderr]    Compiling derivative v2.1.1
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling remain v0.2.2
[INFO] [stderr]    Compiling getset v0.0.9
[INFO] [stderr]     Checking failure v0.1.8
[INFO] [stderr]    Compiling serde v1.0.114
[INFO] [stderr]    Compiling toml v0.5.6
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling cargo-lock v4.0.1
[INFO] [stderr]    Compiling proc-macro-crate v0.1.4
[INFO] [stderr]    Compiling num_enum_derive v0.4.3
[INFO] [stderr]    Compiling built v0.4.2
[INFO] [stderr]    Compiling cpclib-sna v0.4.2-alpha
[INFO] [stderr]    Compiling cpclib-tokens v0.4.2-alpha
[INFO] [stderr]    Compiling cpclib-disc v0.4.2-alpha (/opt/rustwide/workdir)
[INFO] [stderr]     Checking num_enum v0.4.3
[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/cpclib-sna-0.4.2-alpha/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(vec_drain_as_slice)]
[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 `cpclib-sna`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "dbe497b2b52c6e020c8fb397cd3ebc965a07c45946501383a99c86b766063d4c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dbe497b2b52c6e020c8fb397cd3ebc965a07c45946501383a99c86b766063d4c", kill_on_drop: false }`
[INFO] [stdout] dbe497b2b52c6e020c8fb397cd3ebc965a07c45946501383a99c86b766063d4c