[INFO] cloning repository https://github.com/japaric/testd
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/japaric/testd" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjaparic%2Ftestd", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjaparic%2Ftestd'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b964b668c3e6c674b0dfa66ec01ff046ec1c79d5
[INFO] documenting japaric/testd against 1.61.0 for beta-1.62-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjaparic%2Ftestd" "/workspace/builds/worker-28/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-28/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/japaric/testd on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/japaric/testd
[INFO] finished tweaking git repo https://github.com/japaric/testd
[INFO] tweaked toml for git repo https://github.com/japaric/testd written to /workspace/builds/worker-28/source/Cargo.toml
[INFO] crate git repo https://github.com/japaric/testd already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", 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]  Downloading crates ...
[INFO] [stderr]   Downloaded serde_codegen v0.8.21
[INFO] [stderr]   Downloaded bincode v0.6.1
[INFO] [stderr]   Downloaded serde_codegen_internals v0.11.3
[INFO] [stderr]   Downloaded syn v0.10.5
[INFO] [stderr]   Downloaded serde_derive v0.8.21
[INFO] [stderr]   Downloaded serde v0.8.21
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 04a098b3e9bf1533612b0bae832c3db7b1b75a9f7bebda79c434426477694ac6
[INFO] running `Command { std: "docker" "start" "-a" "04a098b3e9bf1533612b0bae832c3db7b1b75a9f7bebda79c434426477694ac6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "04a098b3e9bf1533612b0bae832c3db7b1b75a9f7bebda79c434426477694ac6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "04a098b3e9bf1533612b0bae832c3db7b1b75a9f7bebda79c434426477694ac6", kill_on_drop: false }`
[INFO] [stdout] 04a098b3e9bf1533612b0bae832c3db7b1b75a9f7bebda79c434426477694ac6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0d6ec986a8606c799a8622566a39848d43ad1125d1c4ca5b087a9f2c9b85ba9a
[INFO] running `Command { std: "docker" "start" "-a" "0d6ec986a8606c799a8622566a39848d43ad1125d1c4ca5b087a9f2c9b85ba9a", kill_on_drop: false }`
[INFO] [stderr]    Compiling quote v0.3.10
[INFO] [stderr]    Compiling unicode-xid v0.0.3
[INFO] [stderr]     Checking serde v0.8.21
[INFO] [stderr]     Checking rustc-serialize v0.3.22
[INFO] [stderr]     Checking tempdir v0.3.5
[INFO] [stderr]    Compiling syn v0.10.5
[INFO] [stderr]    Compiling serde_codegen_internals v0.11.3
[INFO] [stderr]    Compiling serde_codegen v0.8.21
[INFO] [stderr]     Checking bincode v0.6.1
[INFO] [stderr]    Compiling serde_derive v0.8.21
[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/serde_derive-0.8.21/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro, proc_macro_lib)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `proc_macro` has been stable since 1.29.0 and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[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/serde_derive-0.8.21/src/lib.rs:1:24
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro, proc_macro_lib)]
[INFO] [stdout]   |                        ^^^^^^^^^^^^^^
[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 compile `serde_derive` due to 3 previous errors
[INFO] running `Command { std: "docker" "inspect" "0d6ec986a8606c799a8622566a39848d43ad1125d1c4ca5b087a9f2c9b85ba9a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0d6ec986a8606c799a8622566a39848d43ad1125d1c4ca5b087a9f2c9b85ba9a", kill_on_drop: false }`
[INFO] [stdout] 0d6ec986a8606c799a8622566a39848d43ad1125d1c4ca5b087a9f2c9b85ba9a