[INFO] fetching crate prty 0.1.1...
[INFO] testing prty-0.1.1 against 1.55.0 for beta-1.56-1
[INFO] extracting crate prty 0.1.1 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate prty 0.1.1 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 prty 0.1.1
[INFO] finished tweaking crates.io crate prty 0.1.1
[INFO] tweaked toml for crates.io crate prty 0.1.1 written to /workspace/builds/worker-3/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]  Downloading crates ...
[INFO] [stderr]   Downloaded peg v0.5.7
[INFO] [stderr]   Downloaded compare v0.1.0
[INFO] [stderr]   Downloaded scopeguard v0.2.0
[INFO] [stderr]   Downloaded quickcheck v0.6.2
[INFO] [stderr]   Downloaded git2 v0.4.4
[INFO] [stderr]   Downloaded libgit2-sys v0.4.6
[INFO] [stderr]   Downloaded git-build-version v0.1.2
[INFO] [stderr]   Downloaded anycat v0.1.2
[INFO] [stderr]   Downloaded quick-error v0.1.4
[INFO] [stderr]   Downloaded measure_time v0.6.0
[INFO] [stderr]   Downloaded prefixopt v0.4.0
[INFO] [stderr]   Downloaded prefixopt_derive v0.4.0
[INFO] [stderr]   Downloaded prty_bitgraph v0.1.1
[INFO] [stderr]   Downloaded map_in_place v0.1.0
[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" "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] f6bc1bdce590cf0ec7e047c86f5638a58617af1c73e2f137d49ff5626c49dbee
[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" "f6bc1bdce590cf0ec7e047c86f5638a58617af1c73e2f137d49ff5626c49dbee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f6bc1bdce590cf0ec7e047c86f5638a58617af1c73e2f137d49ff5626c49dbee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f6bc1bdce590cf0ec7e047c86f5638a58617af1c73e2f137d49ff5626c49dbee", kill_on_drop: false }`
[INFO] [stdout] f6bc1bdce590cf0ec7e047c86f5638a58617af1c73e2f137d49ff5626c49dbee
[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" "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" "build" "--frozen" "--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] 5170416b9753929e5a2e4e182386a0ed5bfdbee0dfb4895e185c0b35febda9bc
[INFO] running `Command { std: "docker" "start" "-a" "5170416b9753929e5a2e4e182386a0ed5bfdbee0dfb4895e185c0b35febda9bc", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling scopeguard v0.2.0
[INFO] [stderr]    Compiling quick-error v0.1.4
[INFO] [stderr]    Compiling prty_fmtmodifier v0.1.1
[INFO] [stderr]    Compiling compare v0.1.0
[INFO] [stderr]    Compiling lzma-sys v0.1.17
[INFO] [stderr]    Compiling peg v0.5.7
[INFO] [stderr]    Compiling libgit2-sys v0.4.6
[INFO] [stderr]    Compiling brotli-sys v0.3.2
[INFO] [stderr]    Compiling measure_time v0.6.0
[INFO] [stderr]    Compiling quickcheck v0.6.2
[INFO] [stderr]    Compiling prty_bitgraph v0.1.1
[INFO] [stderr]    Compiling map_in_place v0.1.0
[INFO] [stderr]    Compiling brotli2 v0.3.2
[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/prty_bitgraph-0.1.1/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(vec_remove_item)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling prefixopt v0.4.0
[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 `prty_bitgraph` 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" "5170416b9753929e5a2e4e182386a0ed5bfdbee0dfb4895e185c0b35febda9bc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5170416b9753929e5a2e4e182386a0ed5bfdbee0dfb4895e185c0b35febda9bc", kill_on_drop: false }`
[INFO] [stdout] 5170416b9753929e5a2e4e182386a0ed5bfdbee0dfb4895e185c0b35febda9bc