[INFO] cloning repository https://github.com/rahcola/rustcafe
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/rahcola/rustcafe" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frahcola%2Frustcafe", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frahcola%2Frustcafe'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 451ec5a60db45b6afb1fbe31404c6089ae631d03
[INFO] documenting rahcola/rustcafe against 1.46.0 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frahcola%2Frustcafe" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/rahcola/rustcafe 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 git repo https://github.com/rahcola/rustcafe
[INFO] finished tweaking git repo https://github.com/rahcola/rustcafe
[INFO] tweaked toml for git repo https://github.com/rahcola/rustcafe written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/rahcola/rustcafe 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] [stderr] error: the lock file /workspace/builds/worker-5/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] 43ced7102f9ad055cc6e6085dac3fa6ede6f36824cafba77c4d297bd9e055619
[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" "43ced7102f9ad055cc6e6085dac3fa6ede6f36824cafba77c4d297bd9e055619", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "43ced7102f9ad055cc6e6085dac3fa6ede6f36824cafba77c4d297bd9e055619", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "43ced7102f9ad055cc6e6085dac3fa6ede6f36824cafba77c4d297bd9e055619", kill_on_drop: false }`
[INFO] [stdout] 43ced7102f9ad055cc6e6085dac3fa6ede6f36824cafba77c4d297bd9e055619
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] [stdout] 3d5f6c7cb4e813d3679bd5fde7339bdd388f0d1a62b42d2a998841cdafd8968e
[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" "3d5f6c7cb4e813d3679bd5fde7339bdd388f0d1a62b42d2a998841cdafd8968e", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v1.0.39
[INFO] [stderr]    Compiling regex v0.2.11
[INFO] [stderr]    Compiling ucd-util v0.1.8
[INFO] [stderr]    Compiling utf8-ranges v1.0.4
[INFO] [stderr]    Compiling regex-syntax v0.4.2
[INFO] [stderr]    Compiling thread_local v0.3.6
[INFO] [stderr]    Compiling aho-corasick v0.6.10
[INFO] [stderr]     Checking tracing v0.1.19
[INFO] [stderr]     Checking want v0.3.0
[INFO] [stderr]     Checking mio v0.6.22
[INFO] [stderr]    Compiling regex-syntax v0.5.6
[INFO] [stderr]     Checking tokio v0.2.22
[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/regex-0.2.11/src/lib.rs:522:34
[INFO] [stdout]     |
[INFO] [stdout] 522 | #![cfg_attr(feature = "pattern", feature(pattern))]
[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 `regex`.
[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" "3d5f6c7cb4e813d3679bd5fde7339bdd388f0d1a62b42d2a998841cdafd8968e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3d5f6c7cb4e813d3679bd5fde7339bdd388f0d1a62b42d2a998841cdafd8968e", kill_on_drop: false }`
[INFO] [stdout] 3d5f6c7cb4e813d3679bd5fde7339bdd388f0d1a62b42d2a998841cdafd8968e