[INFO] fetching crate kunai 0.4.0...
[INFO] testing kunai-0.4.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate kunai 0.4.0 into /workspace/builds/worker-11/source
[INFO] validating manifest of crates.io crate kunai 0.4.0 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 crates.io crate kunai 0.4.0
[INFO] finished tweaking crates.io crate kunai 0.4.0
[INFO] tweaked toml for crates.io crate kunai 0.4.0 written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate crates.io crate kunai 0.4.0 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] f4e7fe088f0056ade4a745c3d26143b80f96b800ac44ea5d36cc97babd6d093d
[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" "f4e7fe088f0056ade4a745c3d26143b80f96b800ac44ea5d36cc97babd6d093d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f4e7fe088f0056ade4a745c3d26143b80f96b800ac44ea5d36cc97babd6d093d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f4e7fe088f0056ade4a745c3d26143b80f96b800ac44ea5d36cc97babd6d093d", kill_on_drop: false }`
[INFO] [stdout] f4e7fe088f0056ade4a745c3d26143b80f96b800ac44ea5d36cc97babd6d093d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] d2e116977ad7f1cf9f04a68aa6b6c0aecd37b4d7e159995f2148ba8c9aac840f
[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" "d2e116977ad7f1cf9f04a68aa6b6c0aecd37b4d7e159995f2148ba8c9aac840f", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.11
[INFO] [stderr]    Compiling rustc-rayon-core v0.3.0
[INFO] [stderr]    Compiling openssl v0.10.26
[INFO] [stderr]    Compiling rustc-ap-graphviz v610.0.0
[INFO] [stderr]    Compiling new_debug_unreachable v1.0.3
[INFO] [stderr]    Compiling curl v0.4.25
[INFO] [stderr]    Compiling rustc-ap-rustc_target v610.0.0
[INFO] [stderr]    Compiling rustc-ap-syntax v610.0.0
[INFO] [stderr]    Compiling rustc-workspace-hack v1.0.0
[INFO] [stderr]    Compiling rustfmt-nightly v1.4.11
[INFO] [stderr]    Compiling home v0.5.1
[INFO] [stderr]    Compiling shell-escape v0.1.4
[INFO] [stderr]    Compiling bytecount v0.6.0
[INFO] [stderr]    Compiling opener v0.4.1
[INFO] [stderr]    Compiling diff v0.1.12
[INFO] [stderr]    Compiling bytesize v1.0.0
[INFO] [stderr]    Compiling crossbeam-utils v0.6.5
[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/rustc-ap-graphviz-610.0.0/lib.rs:277:1
[INFO] [stdout]     |
[INFO] [stdout] 277 | #![feature(rustc_private, nll)]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling lock_api v0.3.2
[INFO] [stderr]    Compiling itertools v0.8.2
[INFO] [stderr]    Compiling rustc-ap-rustc_lexer v610.0.0
[INFO] [stderr]    Compiling tokio-sync v0.1.7
[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 `rustc-ap-graphviz`
[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] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/crossbeam-utils-0.6.5/src/lib.rs:32:34
[INFO] [stdout]    |
[INFO] [stdout] 32 | #![cfg_attr(feature = "nightly", feature(alloc))]
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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/crossbeam-utils-0.6.5/src/lib.rs:33:34
[INFO] [stdout]    |
[INFO] [stdout] 33 | #![cfg_attr(feature = "nightly", feature(cfg_target_has_atomic))]
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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/lock_api-0.3.2/src/lib.rs:89:34
[INFO] [stdout]    |
[INFO] [stdout] 89 | #![cfg_attr(feature = "nightly", 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] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "d2e116977ad7f1cf9f04a68aa6b6c0aecd37b4d7e159995f2148ba8c9aac840f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d2e116977ad7f1cf9f04a68aa6b6c0aecd37b4d7e159995f2148ba8c9aac840f", kill_on_drop: false }`
[INFO] [stdout] d2e116977ad7f1cf9f04a68aa6b6c0aecd37b4d7e159995f2148ba8c9aac840f