[INFO] cloning repository https://github.com/alexcarol/eartrainer-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/alexcarol/eartrainer-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falexcarol%2Feartrainer-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falexcarol%2Feartrainer-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7eeaebf71efe61deb003aad90c0d60cfaccd0032
[INFO] documenting alexcarol/eartrainer-rs 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%2Falexcarol%2Feartrainer-rs" "/workspace/builds/worker-10/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-10/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/alexcarol/eartrainer-rs 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/alexcarol/eartrainer-rs
[INFO] finished tweaking git repo https://github.com/alexcarol/eartrainer-rs
[INFO] tweaked toml for git repo https://github.com/alexcarol/eartrainer-rs written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] crate git repo https://github.com/alexcarol/eartrainer-rs 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]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating git repository `https://github.com/gyng/synthrs`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] 19ca7def138bceadec0fdb88e733ca8f4661923fef1bd6358928d7c6d365967a
[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" "19ca7def138bceadec0fdb88e733ca8f4661923fef1bd6358928d7c6d365967a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "19ca7def138bceadec0fdb88e733ca8f4661923fef1bd6358928d7c6d365967a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "19ca7def138bceadec0fdb88e733ca8f4661923fef1bd6358928d7c6d365967a", kill_on_drop: false }`
[INFO] [stdout] 19ca7def138bceadec0fdb88e733ca8f4661923fef1bd6358928d7c6d365967a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] ccd3905bdfc4673c2d957a9adc5e8b80069331a0ce4d9863a56203d976223464
[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" "ccd3905bdfc4673c2d957a9adc5e8b80069331a0ce4d9863a56203d976223464", kill_on_drop: false }`
[INFO] [stderr]    Compiling num-traits v0.2.8
[INFO] [stderr]    Compiling num-complex v0.2.3
[INFO] [stderr]    Compiling num-iter v0.1.39
[INFO] [stderr]     Checking num-integer v0.1.41
[INFO] [stderr]     Checking num-bigint v0.2.3
[INFO] [stderr]     Checking num-rational v0.2.2
[INFO] [stderr]     Checking num v0.2.0
[INFO] [stderr]     Checking synthrs v0.1.0 (https://github.com/gyng/synthrs?rev=master#1e5573c3)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/git/checkouts/synthrs-a4b8c03c849616c3/1e5573c/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(fn_traits, unboxed_closures)]
[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 `synthrs`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "ccd3905bdfc4673c2d957a9adc5e8b80069331a0ce4d9863a56203d976223464", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ccd3905bdfc4673c2d957a9adc5e8b80069331a0ce4d9863a56203d976223464", kill_on_drop: false }`
[INFO] [stdout] ccd3905bdfc4673c2d957a9adc5e8b80069331a0ce4d9863a56203d976223464