[INFO] cloning repository https://github.com/ThatsGobbles/taggu-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ThatsGobbles/taggu-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FThatsGobbles%2Ftaggu-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FThatsGobbles%2Ftaggu-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 5a400888540da38362bbec2a1a450916aea5024d
[INFO] documenting ThatsGobbles/taggu-rust 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%2FThatsGobbles%2Ftaggu-rust" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ThatsGobbles/taggu-rust 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/ThatsGobbles/taggu-rust
[INFO] finished tweaking git repo https://github.com/ThatsGobbles/taggu-rust
[INFO] tweaked toml for git repo https://github.com/ThatsGobbles/taggu-rust written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/ThatsGobbles/taggu-rust 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-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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] 364f9c47bf0c9a5abc0e35e5730e0c114da4c3067afa299dd4020b0b0ea4158b
[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" "364f9c47bf0c9a5abc0e35e5730e0c114da4c3067afa299dd4020b0b0ea4158b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "364f9c47bf0c9a5abc0e35e5730e0c114da4c3067afa299dd4020b0b0ea4158b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "364f9c47bf0c9a5abc0e35e5730e0c114da4c3067afa299dd4020b0b0ea4158b", kill_on_drop: false }`
[INFO] [stdout] 364f9c47bf0c9a5abc0e35e5730e0c114da4c3067afa299dd4020b0b0ea4158b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 6d5b90047426303480ebcfc613f141fdadcf89dcdc703d4fc4b356ba4fbe697b
[INFO] running `Command { std: "docker" "start" "-a" "6d5b90047426303480ebcfc613f141fdadcf89dcdc703d4fc4b356ba4fbe697b", kill_on_drop: false }`
[INFO] [stderr]     Checking rustc-demangle v0.1.5
[INFO] [stderr]     Checking maplit v1.0.0
[INFO] [stderr]     Checking memchr v2.0.1
[INFO] [stderr]     Checking rand v0.3.18
[INFO] [stderr]    Compiling backtrace-sys v0.1.16
[INFO] [stderr]     Checking yaml-rust v0.4.0
[INFO] [stderr]     Checking aho-corasick v0.6.4
[INFO] [stderr]     Checking regex v0.2.3
[INFO] [stderr]     Checking tempdir v0.3.5
[INFO] [stderr]     Checking env_logger v0.4.3
[INFO] [stderr]     Checking backtrace v0.3.4
[INFO] [stderr]     Checking error-chain v0.12.0
[INFO] [stderr]  Documenting taggu 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(generators, generator_trait)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(type_ascription)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(entry_or_default)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 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 `taggu`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type bin --crate-name taggu 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 env_logger=/opt/rustwide/target/debug/deps/libenv_logger-6ffc975662983661.rmeta --extern error_chain=/opt/rustwide/target/debug/deps/liberror_chain-00ee51f9172401ef.rmeta --extern glob=/opt/rustwide/target/debug/deps/libglob-732e50766ae135c1.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-30a1e68538203258.rmeta --extern maplit=/opt/rustwide/target/debug/deps/libmaplit-cc7bf152d4feff6f.rmeta --extern regex=/opt/rustwide/target/debug/deps/libregex-e98b5d1387d29959.rmeta --extern tempdir=/opt/rustwide/target/debug/deps/libtempdir-5897f8b490375ca5.rmeta --extern yaml_rust=/opt/rustwide/target/debug/deps/libyaml_rust-e60e00bc3d0fddb6.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "6d5b90047426303480ebcfc613f141fdadcf89dcdc703d4fc4b356ba4fbe697b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6d5b90047426303480ebcfc613f141fdadcf89dcdc703d4fc4b356ba4fbe697b", kill_on_drop: false }`
[INFO] [stdout] 6d5b90047426303480ebcfc613f141fdadcf89dcdc703d4fc4b356ba4fbe697b