[INFO] cloning repository https://github.com/PaulGrandperrin/playground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/PaulGrandperrin/playground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FPaulGrandperrin%2Fplayground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FPaulGrandperrin%2Fplayground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 572ff41ccdfa72771a37fd9ab89f37e9b5451041
[INFO] documenting PaulGrandperrin/playground 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%2FPaulGrandperrin%2Fplayground" "/workspace/builds/worker-8/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/PaulGrandperrin/playground 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/PaulGrandperrin/playground
[INFO] finished tweaking git repo https://github.com/PaulGrandperrin/playground
[INFO] tweaked toml for git repo https://github.com/PaulGrandperrin/playground written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/PaulGrandperrin/playground 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-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] d37ecf5cc1e514cb96f72e29d6a6e084e9eeb0b7d64169db6872c017a210b491
[INFO] running `Command { std: "docker" "start" "-a" "d37ecf5cc1e514cb96f72e29d6a6e084e9eeb0b7d64169db6872c017a210b491", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d37ecf5cc1e514cb96f72e29d6a6e084e9eeb0b7d64169db6872c017a210b491", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d37ecf5cc1e514cb96f72e29d6a6e084e9eeb0b7d64169db6872c017a210b491", kill_on_drop: false }`
[INFO] [stdout] d37ecf5cc1e514cb96f72e29d6a6e084e9eeb0b7d64169db6872c017a210b491
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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] 668c60f5b470039120b103d2503a29dbfd33813455aa837192efb2f4bdbf1ee5
[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" "668c60f5b470039120b103d2503a29dbfd33813455aa837192efb2f4bdbf1ee5", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.55
[INFO] [stderr]    Compiling syn v0.15.34
[INFO] [stderr]    Compiling cc v1.0.37
[INFO] [stderr]    Compiling byteorder v1.3.1
[INFO] [stderr]     Checking rustc-demangle v0.1.14
[INFO] [stderr]    Compiling serde v1.0.91
[INFO] [stderr]    Compiling num-rational v0.2.1
[INFO] [stderr]    Compiling num-complex v0.2.1
[INFO] [stderr]     Checking either v1.5.2
[INFO] [stderr]    Compiling num-traits v0.2.8
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling backtrace v0.3.26
[INFO] [stderr]    Compiling num-iter v0.1.39
[INFO] [stderr]    Compiling bincode v1.1.4
[INFO] [stderr]     Checking itertools v0.8.0
[INFO] [stderr]    Compiling backtrace-sys v0.1.28
[INFO] [stderr]     Checking dirs v1.0.5
[INFO] [stderr]     Checking iovec v0.1.2
[INFO] [stderr]     Checking term v0.5.2
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]     Checking num-bigint v0.2.2
[INFO] [stderr]     Checking color-backtrace v0.1.3
[INFO] [stderr]     Checking num v0.2.0
[INFO] [stderr]    Compiling synstructure v0.10.2
[INFO] [stderr]    Compiling serde_derive v1.0.91
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]     Checking failure v0.1.5
[INFO] [stderr]     Checking exitfailure v0.5.1
[INFO] [stderr]  Documenting playground 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(
[INFO] [stdout] 2 | |     trivial_bounds,
[INFO] [stdout] 3 | |     try_from,
[INFO] [stdout] 4 | |     non_exhaustive,
[INFO] [stdout] ... |
[INFO] [stdout] 8 | |     never_type
[INFO] [stdout] 9 | | )]
[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 `playground`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name playground 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 bincode=/opt/rustwide/target/debug/deps/libbincode-f86d3b7e2cd5c33b.rmeta --extern bytes=/opt/rustwide/target/debug/deps/libbytes-faf2f29453f8deb9.rmeta --extern color_backtrace=/opt/rustwide/target/debug/deps/libcolor_backtrace-c39a5475cc04a1e0.rmeta --extern exitfailure=/opt/rustwide/target/debug/deps/libexitfailure-2852ce706566877c.rmeta --extern failure=/opt/rustwide/target/debug/deps/libfailure-cced35f31a7995d7.rmeta --extern itertools=/opt/rustwide/target/debug/deps/libitertools-4d609b64252e263e.rmeta --extern num=/opt/rustwide/target/debug/deps/libnum-3fb07cf1a302bbb4.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-29dcbb2e9f3b3290.rmeta --cap-lints=warn --crate-version 0.1.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "668c60f5b470039120b103d2503a29dbfd33813455aa837192efb2f4bdbf1ee5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "668c60f5b470039120b103d2503a29dbfd33813455aa837192efb2f4bdbf1ee5", kill_on_drop: false }`
[INFO] [stdout] 668c60f5b470039120b103d2503a29dbfd33813455aa837192efb2f4bdbf1ee5
