[INFO] cloning repository https://github.com/tuomas56/pixelengine
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tuomas56/pixelengine" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftuomas56%2Fpixelengine", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftuomas56%2Fpixelengine'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b512b11fc66f1f0161952842da1b61c8fde3dab5
[INFO] documenting tuomas56/pixelengine 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%2Ftuomas56%2Fpixelengine" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tuomas56/pixelengine 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/tuomas56/pixelengine
[INFO] finished tweaking git repo https://github.com/tuomas56/pixelengine
[INFO] tweaked toml for git repo https://github.com/tuomas56/pixelengine written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/tuomas56/pixelengine 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]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 31830b6f78e2b238d3e5eac75060ad2d029b854b2491007644cf098b7c96fd6b
[INFO] running `Command { std: "docker" "start" "-a" "31830b6f78e2b238d3e5eac75060ad2d029b854b2491007644cf098b7c96fd6b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "31830b6f78e2b238d3e5eac75060ad2d029b854b2491007644cf098b7c96fd6b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "31830b6f78e2b238d3e5eac75060ad2d029b854b2491007644cf098b7c96fd6b", kill_on_drop: false }`
[INFO] [stdout] 31830b6f78e2b238d3e5eac75060ad2d029b854b2491007644cf098b7c96fd6b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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] 68cd9cd75abfaf5b05a109fcaa785f6ca6b79f8d9b4d452c1f2bf316cd1ec1a3
[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" "68cd9cd75abfaf5b05a109fcaa785f6ca6b79f8d9b4d452c1f2bf316cd1ec1a3", kill_on_drop: false }`
[INFO] [stderr]     Checking rand_core v0.3.0
[INFO] [stderr]    Compiling autocfg v0.1.1
[INFO] [stderr]     Checking byteorder v1.2.7
[INFO] [stderr]    Compiling nix v0.11.1
[INFO] [stderr]    Compiling num-derive v0.2.4
[INFO] [stderr]    Compiling num-rational v0.2.1
[INFO] [stderr]     Checking safe-transmute v0.10.1
[INFO] [stderr]    Compiling libloading v0.5.0
[INFO] [stderr]     Checking log v0.4.6
[INFO] [stderr]     Checking crossbeam-utils v0.6.5
[INFO] [stderr]     Checking unreachable v1.0.0
[INFO] [stderr]    Compiling wayland-scanner v0.20.12
[INFO] [stderr]     Checking gif v0.10.1
[INFO] [stderr]     Checking num_cpus v1.10.0
[INFO] [stderr]     Checking memmap v0.6.2
[INFO] [stderr]     Checking shared_library v0.1.9
[INFO] [stderr]     Checking smallvec v0.6.7
[INFO] [stderr]     Checking crossbeam-epoch v0.3.1
[INFO] [stderr]    Compiling rand_pcg v0.1.1
[INFO] [stderr]    Compiling parking_lot_core v0.3.1
[INFO] [stderr]     Checking backtrace-sys v0.1.28
[INFO] [stderr]     Checking approx v0.3.1
[INFO] [stderr]     Checking ordered-float v1.0.1
[INFO] [stderr]     Checking x11-dl v2.18.3
[INFO] [stderr]     Checking rand_os v0.1.1
[INFO] [stderr]     Checking rand_xorshift v0.1.1
[INFO] [stderr]     Checking rand_hc v0.1.0
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]     Checking rand v0.5.6
[INFO] [stderr]    Compiling gl_generator v0.9.0
[INFO] [stderr]     Checking deflate v0.7.19
[INFO] [stderr]     Checking rustc-hash v1.0.1
[INFO] [stderr]     Checking stb_truetype v0.2.6
[INFO] [stderr]     Checking osmesa-sys v0.1.2
[INFO] [stderr]     Checking crossbeam-epoch v0.7.1
[INFO] [stderr]    Compiling syn v0.15.27
[INFO] [stderr]     Checking crossbeam-deque v0.2.0
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.4
[INFO] [stderr]    Compiling backtrace v0.3.13
[INFO] [stderr]     Checking rayon-core v1.4.1
[INFO] [stderr]    Compiling wayland-client v0.20.12
[INFO] [stderr]    Compiling wayland-protocols v0.20.12
[INFO] [stderr]     Checking dlib v0.4.1
[INFO] [stderr]     Checking crossbeam-deque v0.7.1
[INFO] [stderr]     Checking wayland-sys v0.20.12
[INFO] [stderr]     Checking rayon v1.0.3
[INFO] [stderr]     Checking rusttype v0.7.4
[INFO] [stderr]     Checking wayland-commons v0.20.12
[INFO] [stderr]     Checking png v0.14.0
[INFO] [stderr]    Compiling glutin v0.17.0
[INFO] [stderr]    Compiling glium v0.22.0
[INFO] [stderr]     Checking parking_lot v0.6.4
[INFO] [stderr]     Checking tempfile v3.0.8
[INFO] [stderr]     Checking jpeg-decoder v0.1.15
[INFO] [stderr]     Checking smithay-client-toolkit v0.2.6
[INFO] [stderr]     Checking winit v0.16.2
[INFO] [stderr]     Checking tiff v0.2.2
[INFO] [stderr]     Checking image v0.21.0
[INFO] [stderr]  Documenting pixelengine v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(let_chains)]
[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 `pixelengine`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name pixelengine src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern glium=/opt/rustwide/target/debug/deps/libglium-c9a02c48e411ada6.rmeta --extern image=/opt/rustwide/target/debug/deps/libimage-97a01bb58e2ff8b6.rmeta --extern rusttype=/opt/rustwide/target/debug/deps/librusttype-47f291c8223f4e42.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "68cd9cd75abfaf5b05a109fcaa785f6ca6b79f8d9b4d452c1f2bf316cd1ec1a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "68cd9cd75abfaf5b05a109fcaa785f6ca6b79f8d9b4d452c1f2bf316cd1ec1a3", kill_on_drop: false }`
[INFO] [stdout] 68cd9cd75abfaf5b05a109fcaa785f6ca6b79f8d9b4d452c1f2bf316cd1ec1a3