[INFO] cloning repository https://github.com/hegza/serpent-cli
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/hegza/serpent-cli" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhegza%2Fserpent-cli", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhegza%2Fserpent-cli'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 83103be6a1a6e47a800a631cbf59046e862d3f57
[INFO] documenting hegza/serpent-cli against 1.47.0 for beta-1.48-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhegza%2Fserpent-cli" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/hegza/serpent-cli on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/hegza/serpent-cli
[INFO] finished tweaking git repo https://github.com/hegza/serpent-cli
[INFO] tweaked toml for git repo https://github.com/hegza/serpent-cli written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/hegza/serpent-cli already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7739dd77f96ad27b23555a60ebc7f13578a653cebf4204ff347820fb00398bd6
[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" "7739dd77f96ad27b23555a60ebc7f13578a653cebf4204ff347820fb00398bd6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7739dd77f96ad27b23555a60ebc7f13578a653cebf4204ff347820fb00398bd6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7739dd77f96ad27b23555a60ebc7f13578a653cebf4204ff347820fb00398bd6", kill_on_drop: false }`
[INFO] [stdout] 7739dd77f96ad27b23555a60ebc7f13578a653cebf4204ff347820fb00398bd6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+1.47.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8be6269b34eb5097c2e4226846cca724c13cba50da41566c801317947a7341cd
[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" "8be6269b34eb5097c2e4226846cca724c13cba50da41566c801317947a7341cd", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.44
[INFO] [stderr]    Compiling serde v1.0.116
[INFO] [stderr]     Checking smallvec v1.4.2
[INFO] [stderr]     Checking either v1.6.1
[INFO] [stderr]    Compiling rustc-rayon-core v0.3.0
[INFO] [stderr]    Compiling siphasher v0.3.3
[INFO] [stderr]     Checking rustc-ap-rustc_graphviz v673.0.0
[INFO] [stderr]     Checking stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling regex-syntax v0.6.20
[INFO] [stderr]     Checking scoped-tls v1.0.0
[INFO] [stderr]    Compiling lalrpop-util v0.19.1
[INFO] [stderr]     Checking unic-char-range v0.9.0
[INFO] [stderr]     Checking unic-common v0.9.0
[INFO] [stderr]     Checking unicode-xid v0.2.1
[INFO] [stderr]    Compiling rustfmt v0.10.0
[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/smallvec-1.4.2/src/lib.rs:74:32
[INFO] [stdout]    |
[INFO] [stdout] 74 | #![cfg_attr(feature = "union", feature(untagged_unions))]
[INFO] [stdout]    |                                ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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/smallvec-1.4.2/src/lib.rs:77:37
[INFO] [stdout]    |
[INFO] [stdout] 77 | #![cfg_attr(feature = "may_dangle", feature(dropck_eyepatch))]
[INFO] [stdout]    |                                     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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/rustc-ap-rustc_graphviz-673.0.0/lib.rs:278:1
[INFO] [stdout]     |
[INFO] [stdout] 278 | #![feature(rustc_private, nll)]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking unicode_names2 v0.4.0
[INFO] [stderr]     Checking diff v0.1.12
[INFO] [stderr]     Checking normalize-line-endings v0.3.0
[INFO] [stderr]     Checking fs-err v2.5.0
[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 `rustc-ap-rustc_graphviz`.
[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] [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: build failed
[INFO] running `Command { std: "docker" "inspect" "8be6269b34eb5097c2e4226846cca724c13cba50da41566c801317947a7341cd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8be6269b34eb5097c2e4226846cca724c13cba50da41566c801317947a7341cd", kill_on_drop: false }`
[INFO] [stdout] 8be6269b34eb5097c2e4226846cca724c13cba50da41566c801317947a7341cd
