[INFO] fetching crate iomrascalai 0.1.7...
[INFO] checking iomrascalai-0.1.7 against 1.55.0 for beta-1.56-3
[INFO] extracting crate iomrascalai 0.1.7 into /workspace/builds/worker-40/source
[INFO] validating manifest of crates.io crate iomrascalai 0.1.7 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate iomrascalai 0.1.7
[INFO] finished tweaking crates.io crate iomrascalai 0.1.7
[INFO] tweaked toml for crates.io crate iomrascalai 0.1.7 written to /workspace/builds/worker-40/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--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-40/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6293b18685ae7315986d9eba2a924acfd1f8809d5202cfe806a36b90077cb205
[INFO] running `Command { std: "docker" "start" "-a" "6293b18685ae7315986d9eba2a924acfd1f8809d5202cfe806a36b90077cb205", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6293b18685ae7315986d9eba2a924acfd1f8809d5202cfe806a36b90077cb205", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6293b18685ae7315986d9eba2a924acfd1f8809d5202cfe806a36b90077cb205", kill_on_drop: false }`
[INFO] [stdout] 6293b18685ae7315986d9eba2a924acfd1f8809d5202cfe806a36b90077cb205
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c64cdd680f11c0483eae8d3b0b8258524ea5d581c959f0090b237ce8125cb193
[INFO] running `Command { std: "docker" "start" "-a" "c64cdd680f11c0483eae8d3b0b8258524ea5d581c959f0090b237ce8125cb193", kill_on_drop: false }`
[INFO] [stderr]     Checking rustc-serialize v0.3.24
[INFO] [stderr]     Checking time v0.3.3
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-bigint v0.4.2
[INFO] [stderr]    Compiling num-rational v0.4.0
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]     Checking getrandom v0.2.3
[INFO] [stderr]    Compiling regex v0.2.11
[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/regex-0.2.11/src/lib.rs:522:34
[INFO] [stdout]     |
[INFO] [stdout] 522 | #![cfg_attr(feature = "pattern", feature(pattern))]
[INFO] [stdout]     |                                  ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking rand_core v0.6.3
[INFO] [stderr]     Checking rand_chacha v0.3.1
[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 `regex` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "c64cdd680f11c0483eae8d3b0b8258524ea5d581c959f0090b237ce8125cb193", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c64cdd680f11c0483eae8d3b0b8258524ea5d581c959f0090b237ce8125cb193", kill_on_drop: false }`
[INFO] [stdout] c64cdd680f11c0483eae8d3b0b8258524ea5d581c959f0090b237ce8125cb193
