[INFO] fetching crate free-algebra 0.1.0...
[INFO] documenting free-algebra-0.1.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate free-algebra 0.1.0 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate free-algebra 0.1.0 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 crates.io crate free-algebra 0.1.0
[INFO] finished tweaking crates.io crate free-algebra 0.1.0
[INFO] tweaked toml for crates.io crate free-algebra 0.1.0 written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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 derivative v1.0.4
[INFO] [stderr]   Downloaded maths-traits v0.2.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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] 7e380320df16e2ce3dbbbbf1181f0422f3ff300425babfbf730463f4fe0e6990
[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" "7e380320df16e2ce3dbbbbf1181f0422f3ff300425babfbf730463f4fe0e6990", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7e380320df16e2ce3dbbbbf1181f0422f3ff300425babfbf730463f4fe0e6990", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7e380320df16e2ce3dbbbbf1181f0422f3ff300425babfbf730463f4fe0e6990", kill_on_drop: false }`
[INFO] [stdout] 7e380320df16e2ce3dbbbbf1181f0422f3ff300425babfbf730463f4fe0e6990
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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] cd0dd7f3f6055ca8eecec1be6feff4eaa5135e8a644f04916988491dcd627cee
[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" "cd0dd7f3f6055ca8eecec1be6feff4eaa5135e8a644f04916988491dcd627cee", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking maths-traits v0.2.1
[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/maths-traits-0.2.1/src/lib.rs:317:1
[INFO] [stdout]     |
[INFO] [stdout] 317 | #![feature(trait_alias)]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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/maths-traits-0.2.1/src/lib.rs:318:1
[INFO] [stdout]     |
[INFO] [stdout] 318 | #![feature(specialization)]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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/maths-traits-0.2.1/src/lib.rs:319:1
[INFO] [stdout]     |
[INFO] [stdout] 319 | #![feature(extra_log_consts)]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 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 `maths-traits`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "cd0dd7f3f6055ca8eecec1be6feff4eaa5135e8a644f04916988491dcd627cee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cd0dd7f3f6055ca8eecec1be6feff4eaa5135e8a644f04916988491dcd627cee", kill_on_drop: false }`
[INFO] [stdout] cd0dd7f3f6055ca8eecec1be6feff4eaa5135e8a644f04916988491dcd627cee