[INFO] cloning repository https://github.com/jiegec/ebnf-tools
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jiegec/ebnf-tools" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjiegec%2Febnf-tools", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjiegec%2Febnf-tools'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0b81c9ecbfe92f94349a42cac65666bda4ebf99c
[INFO] testing jiegec/ebnf-tools against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjiegec%2Febnf-tools" "/workspace/builds/worker-13/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-13/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jiegec/ebnf-tools on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/jiegec/ebnf-tools
[INFO] finished tweaking git repo https://github.com/jiegec/ebnf-tools
[INFO] tweaked toml for git repo https://github.com/jiegec/ebnf-tools written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] crate git repo https://github.com/jiegec/ebnf-tools already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2babac8870db87083c804cc5716f61d345f0d3aa6882a7bd637c79a28fcff0e8
[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" "2babac8870db87083c804cc5716f61d345f0d3aa6882a7bd637c79a28fcff0e8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2babac8870db87083c804cc5716f61d345f0d3aa6882a7bd637c79a28fcff0e8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2babac8870db87083c804cc5716f61d345f0d3aa6882a7bd637c79a28fcff0e8", kill_on_drop: false }`
[INFO] [stdout] 2babac8870db87083c804cc5716f61d345f0d3aa6882a7bd637c79a28fcff0e8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "RUSTFLAGS=--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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 73f23f2bbc8e2b8dc04829ff5034dab4b80af29927023a2cf610aaef4dedd4b4
[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" "73f23f2bbc8e2b8dc04829ff5034dab4b80af29927023a2cf610aaef4dedd4b4", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.5
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]    Compiling serde v1.0.101
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]    Compiling smallvec v0.6.10
[INFO] [stderr]    Compiling nodrop v0.1.14
[INFO] [stderr]    Compiling static_assertions v0.3.4
[INFO] [stderr]    Compiling hashbrown v0.5.0
[INFO] [stderr]    Compiling bitset v0.1.0 (https://github.com/MashPlant/bitset#a20d7b54)
[INFO] [stderr]    Compiling getrandom v0.1.12
[INFO] [stderr]    Compiling print v0.1.0 (https://github.com/MashPlant/re2dfa#d3544ab7)
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling typed-arena v1.6.1
[INFO] [stderr]    Compiling nom v5.0.1
[INFO] [stderr]    Compiling c2-chacha v0.2.2
[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/smallvec-0.6.10/lib.rs:33:32
[INFO] [stdout]    |
[INFO] [stdout] 33 | #![cfg_attr(feature = "union", feature(untagged_unions))]
[INFO] [stdout]    |                                ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling lexical-core v0.4.6
[INFO] [stderr]    Compiling clap v2.33.0
[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 `smallvec`
[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" "73f23f2bbc8e2b8dc04829ff5034dab4b80af29927023a2cf610aaef4dedd4b4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "73f23f2bbc8e2b8dc04829ff5034dab4b80af29927023a2cf610aaef4dedd4b4", kill_on_drop: false }`
[INFO] [stdout] 73f23f2bbc8e2b8dc04829ff5034dab4b80af29927023a2cf610aaef4dedd4b4