[INFO] cloning repository https://github.com/mgdm/rrt
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mgdm/rrt" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmgdm%2Frrt", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmgdm%2Frrt'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 85a6af7711c77651bad4e398a48bb36f8a87e6aa
[INFO] documenting mgdm/rrt against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmgdm%2Frrt" "/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/mgdm/rrt on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/mgdm/rrt
[INFO] finished tweaking git repo https://github.com/mgdm/rrt
[INFO] tweaked toml for git repo https://github.com/mgdm/rrt written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/mgdm/rrt already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded num-rational v0.1.35
[INFO] [stderr]   Downloaded num-bigint v0.1.35
[INFO] [stderr]   Downloaded quote v0.3.10
[INFO] [stderr]   Downloaded serde_json v0.8.4
[INFO] [stderr]   Downloaded num-complex v0.1.35
[INFO] [stderr]   Downloaded serde_codegen_internals v0.11.3
[INFO] [stderr]   Downloaded serde v0.8.21
[INFO] [stderr]   Downloaded serde_codegen v0.8.21
[INFO] [stderr]   Downloaded serde_derive v0.8.21
[INFO] [stderr]   Downloaded syn v0.10.5
[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" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0d15170a22caed8e6b625298da742718fde78228835a7c09792541f54c85b70f
[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" "0d15170a22caed8e6b625298da742718fde78228835a7c09792541f54c85b70f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0d15170a22caed8e6b625298da742718fde78228835a7c09792541f54c85b70f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0d15170a22caed8e6b625298da742718fde78228835a7c09792541f54c85b70f", kill_on_drop: false }`
[INFO] [stdout] 0d15170a22caed8e6b625298da742718fde78228835a7c09792541f54c85b70f
[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" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b681e8292892ffe508a18fa1e9ddacc105541e4e59df27320e472b5890ec8133
[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" "b681e8292892ffe508a18fa1e9ddacc105541e4e59df27320e472b5890ec8133", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.18
[INFO] [stderr]     Checking num-traits v0.1.36
[INFO] [stderr]     Checking rustc-serialize v0.3.22
[INFO] [stderr]    Compiling unicode-xid v0.0.3
[INFO] [stderr]    Compiling quote v0.3.10
[INFO] [stderr]     Checking strsim v0.5.2
[INFO] [stderr]     Checking serde v0.8.21
[INFO] [stderr]     Checking itoa v0.1.1
[INFO] [stderr]     Checking dtoa v0.2.2
[INFO] [stderr]    Compiling syn v0.10.5
[INFO] [stderr]     Checking thread-id v2.0.0
[INFO] [stderr]     Checking memchr v0.1.11
[INFO] [stderr]     Checking rand v0.3.15
[INFO] [stderr]     Checking thread_local v0.2.7
[INFO] [stderr]     Checking aho-corasick v0.5.3
[INFO] [stderr]     Checking num-integer v0.1.32
[INFO] [stderr]     Checking num-iter v0.1.32
[INFO] [stderr]     Checking regex v0.1.80
[INFO] [stderr]    Compiling serde_codegen_internals v0.11.3
[INFO] [stderr]    Compiling serde_codegen v0.8.21
[INFO] [stderr]     Checking serde_json v0.8.4
[INFO] [stderr]     Checking num-bigint v0.1.35
[INFO] [stderr]     Checking num-complex v0.1.35
[INFO] [stderr]     Checking docopt v0.6.86
[INFO] [stderr]     Checking num-rational v0.1.35
[INFO] [stderr]     Checking num v0.1.36
[INFO] [stderr]    Compiling serde_derive v0.8.21
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta 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] 
[INFO] [stdout] error: aborting due to previous error
[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`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "b681e8292892ffe508a18fa1e9ddacc105541e4e59df27320e472b5890ec8133", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b681e8292892ffe508a18fa1e9ddacc105541e4e59df27320e472b5890ec8133", kill_on_drop: false }`
[INFO] [stdout] b681e8292892ffe508a18fa1e9ddacc105541e4e59df27320e472b5890ec8133