[INFO] cloning repository https://github.com/japaric/xargo
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/japaric/xargo" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjaparic%2Fxargo", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjaparic%2Fxargo'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 35d02768e8320d13518b03ab15b6a07231247cd6
[INFO] testing japaric/xargo against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjaparic%2Fxargo" "/workspace/builds/worker-14/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-14/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/japaric/xargo 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/japaric/xargo
[INFO] finished tweaking git repo https://github.com/japaric/xargo
[INFO] tweaked toml for git repo https://github.com/japaric/xargo written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] crate git repo https://github.com/japaric/xargo 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-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 28e287d27b2489ed122278c710e130e8ecc80fa00d6193cbf21b1a5f1ac685eb
[INFO] running `Command { std: "docker" "start" "-a" "28e287d27b2489ed122278c710e130e8ecc80fa00d6193cbf21b1a5f1ac685eb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "28e287d27b2489ed122278c710e130e8ecc80fa00d6193cbf21b1a5f1ac685eb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "28e287d27b2489ed122278c710e130e8ecc80fa00d6193cbf21b1a5f1ac685eb", kill_on_drop: false }`
[INFO] [stdout] 28e287d27b2489ed122278c710e130e8ecc80fa00d6193cbf21b1a5f1ac685eb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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] 6c8d4abf191e0d134bc62ab2b4f8b01923378847995654d8ca25877bbdb1cfd1
[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" "6c8d4abf191e0d134bc62ab2b4f8b01923378847995654d8ca25877bbdb1cfd1", kill_on_drop: false }`
[INFO] [stderr]    Compiling gimli v0.22.0
[INFO] [stderr]    Compiling adler v0.2.3
[INFO] [stderr]    Compiling object v0.20.0
[INFO] [stderr]    Compiling serde_json v1.0.57
[INFO] [stderr]    Compiling itoa v0.4.6
[INFO] [stderr]    Compiling remove_dir_all v0.5.3
[INFO] [stderr]    Compiling xargo v0.3.22 (/opt/rustwide/workdir)
[INFO] [stderr]    Compiling error-chain v0.12.2
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]    Compiling dirs-sys v0.3.5
[INFO] [stderr]    Compiling fs2 v0.4.3
[INFO] [stderr]    Compiling miniz_oxide v0.4.0
[INFO] [stderr]    Compiling dirs v3.0.1
[INFO] [stderr]    Compiling tempdir v0.3.7
[INFO] [stderr]    Compiling addr2line v0.13.0
[INFO] [stderr]    Compiling backtrace v0.3.50
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 32.27s
[INFO] running `Command { std: "docker" "inspect" "6c8d4abf191e0d134bc62ab2b4f8b01923378847995654d8ca25877bbdb1cfd1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6c8d4abf191e0d134bc62ab2b4f8b01923378847995654d8ca25877bbdb1cfd1", kill_on_drop: false }`
[INFO] [stdout] 6c8d4abf191e0d134bc62ab2b4f8b01923378847995654d8ca25877bbdb1cfd1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 47f94771d83767673b92bf89be0be2012567bc8e4840c0a71622df1ec2d37e4b
[INFO] running `Command { std: "docker" "start" "-a" "47f94771d83767673b92bf89be0be2012567bc8e4840c0a71622df1ec2d37e4b", kill_on_drop: false }`
[INFO] [stderr]    Compiling smallvec v1.4.1
[INFO] [stderr]    Compiling instant v0.1.6
[INFO] [stderr]    Compiling lock_api v0.4.1
[INFO] [stderr]    Compiling parking_lot_core v0.8.0
[INFO] [stderr]    Compiling parking_lot v0.11.0
[INFO] [stderr]    Compiling xargo v0.3.22 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> tests/smoke.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(const_fn)]
[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 `xargo`
[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" "47f94771d83767673b92bf89be0be2012567bc8e4840c0a71622df1ec2d37e4b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "47f94771d83767673b92bf89be0be2012567bc8e4840c0a71622df1ec2d37e4b", kill_on_drop: false }`
[INFO] [stdout] 47f94771d83767673b92bf89be0be2012567bc8e4840c0a71622df1ec2d37e4b