[INFO] cloning repository https://github.com/vasily-kirichenko/failure_perf_issue
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/vasily-kirichenko/failure_perf_issue" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvasily-kirichenko%2Ffailure_perf_issue", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvasily-kirichenko%2Ffailure_perf_issue'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] cd2d108809f03ee3a02636d8c184f5f731abe8c4
[INFO] documenting vasily-kirichenko/failure_perf_issue 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%2Fvasily-kirichenko%2Ffailure_perf_issue" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/vasily-kirichenko/failure_perf_issue 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/vasily-kirichenko/failure_perf_issue
[INFO] finished tweaking git repo https://github.com/vasily-kirichenko/failure_perf_issue
[INFO] tweaked toml for git repo https://github.com/vasily-kirichenko/failure_perf_issue written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/vasily-kirichenko/failure_perf_issue 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-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] 7a20c6ac27e092972fe23a7a147de0fbc01bb3b2d7dc30731e6bd6cac18b20b5
[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" "7a20c6ac27e092972fe23a7a147de0fbc01bb3b2d7dc30731e6bd6cac18b20b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7a20c6ac27e092972fe23a7a147de0fbc01bb3b2d7dc30731e6bd6cac18b20b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7a20c6ac27e092972fe23a7a147de0fbc01bb3b2d7dc30731e6bd6cac18b20b5", kill_on_drop: false }`
[INFO] [stdout] 7a20c6ac27e092972fe23a7a147de0fbc01bb3b2d7dc30731e6bd6cac18b20b5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] da70e620719cbec436bf11bb873528e109bd3c9e4f3631b6316ad7fd8a2a620d
[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" "da70e620719cbec436bf11bb873528e109bd3c9e4f3631b6316ad7fd8a2a620d", kill_on_drop: false }`
[INFO] [stderr]    Compiling cc v1.0.12
[INFO] [stderr]     Checking scoped-tls v0.1.1
[INFO] [stderr]     Checking rustc-demangle v0.1.7
[INFO] [stderr]     Checking serde v1.0.43
[INFO] [stderr]     Checking iovec v0.1.2
[INFO] [stderr]     Checking net2 v0.2.32
[INFO] [stderr]     Checking crossbeam-utils v0.3.2
[INFO] [stderr]     Checking tokio-service v0.1.0
[INFO] [stderr]     Checking relay v0.1.1
[INFO] [stderr]    Compiling proc-macro2 v0.3.7
[INFO] [stderr]     Checking futures-cpupool v0.1.8
[INFO] [stderr]     Checking tokio-timer v0.2.1
[INFO] [stderr]    Compiling synstructure v0.6.1
[INFO] [stderr]     Checking crossbeam-epoch v0.4.1
[INFO] [stderr]     Checking bytes v0.4.6
[INFO] [stderr]     Checking mio v0.6.14
[INFO] [stderr]     Checking crossbeam-deque v0.3.0
[INFO] [stderr]     Checking tokio-io v0.1.6
[INFO] [stderr]    Compiling quote v0.5.2
[INFO] [stderr]     Checking tokio-threadpool v0.1.2
[INFO] [stderr]    Compiling syn v0.13.1
[INFO] [stderr]    Compiling failure_derive v0.1.1
[INFO] [stderr]    Compiling backtrace-sys v0.1.16
[INFO] [stderr]     Checking tokio-reactor v0.1.1
[INFO] [stderr]     Checking tokio-udp v0.1.0
[INFO] [stderr]     Checking tokio-tcp v0.1.0
[INFO] [stderr]     Checking tokio v0.1.5
[INFO] [stderr]     Checking tokio-core v0.1.17
[INFO] [stderr]     Checking tokio-proto v0.1.1
[INFO] [stderr]    Compiling serde_derive_internals v0.23.1
[INFO] [stderr]     Checking hyper v0.11.25
[INFO] [stderr]    Compiling serde_derive v1.0.43
[INFO] [stderr]     Checking serde_json v1.0.16
[INFO] [stderr]     Checking backtrace v0.3.6
[INFO] [stderr]     Checking failure v0.1.1
[INFO] [stderr]  Documenting failure_perf_issue v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(iterator_find_map)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[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: Could not document `failure_perf_issue`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type bin --crate-name failure_perf_issue src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern failure=/opt/rustwide/target/debug/deps/libfailure-63dba7f42d030e82.rmeta --extern futures=/opt/rustwide/target/debug/deps/libfutures-6249a1f66b4cd952.rmeta --extern hyper=/opt/rustwide/target/debug/deps/libhyper-460c02e5ad0a5d6f.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-49314d11522260e6.rmeta --extern serde_derive=/opt/rustwide/target/debug/deps/libserde_derive-f7e7de0026ba1710.so --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-2d282f51dbfcef1a.rmeta --extern tokio_core=/opt/rustwide/target/debug/deps/libtokio_core-67cbdf560f44736a.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "da70e620719cbec436bf11bb873528e109bd3c9e4f3631b6316ad7fd8a2a620d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "da70e620719cbec436bf11bb873528e109bd3c9e4f3631b6316ad7fd8a2a620d", kill_on_drop: false }`
[INFO] [stdout] da70e620719cbec436bf11bb873528e109bd3c9e4f3631b6316ad7fd8a2a620d