[INFO] fetching crate wu-diff 0.1.2...
[INFO] testing wu-diff-0.1.2 against 1.55.0 for beta-1.56-1
[INFO] extracting crate wu-diff 0.1.2 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate wu-diff 0.1.2 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 wu-diff 0.1.2
[INFO] finished tweaking crates.io crate wu-diff 0.1.2
[INFO] tweaked toml for crates.io crate wu-diff 0.1.2 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate crates.io crate wu-diff 0.1.2 already has a lockfile, it will not be regenerated
[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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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] 474026c025002764f669a4a8c8729f1c494b81684eda1aec2053ecb021d8518c
[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" "474026c025002764f669a4a8c8729f1c494b81684eda1aec2053ecb021d8518c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "474026c025002764f669a4a8c8729f1c494b81684eda1aec2053ecb021d8518c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "474026c025002764f669a4a8c8729f1c494b81684eda1aec2053ecb021d8518c", kill_on_drop: false }`
[INFO] [stdout] 474026c025002764f669a4a8c8729f1c494b81684eda1aec2053ecb021d8518c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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] [stdout] 6441779a4bf3045c64a72649fe9b1870991f8a6afa373701bad4b02c20c43a38
[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" "6441779a4bf3045c64a72649fe9b1870991f8a6afa373701bad4b02c20c43a38", kill_on_drop: false }`
[INFO] [stderr]    Compiling wu-diff v0.1.2 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.70s
[INFO] running `Command { std: "docker" "inspect" "6441779a4bf3045c64a72649fe9b1870991f8a6afa373701bad4b02c20c43a38", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6441779a4bf3045c64a72649fe9b1870991f8a6afa373701bad4b02c20c43a38", kill_on_drop: false }`
[INFO] [stdout] 6441779a4bf3045c64a72649fe9b1870991f8a6afa373701bad4b02c20c43a38
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b12f0b2338d4225b9bddaded3935e6aefc58b4aea15b3eff34eddd4f3f7d5a93
[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" "b12f0b2338d4225b9bddaded3935e6aefc58b4aea15b3eff34eddd4f3f7d5a93", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.40
[INFO] [stderr]    Compiling cfg-if v0.1.2
[INFO] [stderr]    Compiling num-traits v0.2.2
[INFO] [stderr]    Compiling lazy_static v1.0.0
[INFO] [stderr]    Compiling byteorder v1.2.2
[INFO] [stderr]    Compiling nodrop v0.1.12
[INFO] [stderr]    Compiling either v1.5.0
[INFO] [stderr]    Compiling cc v1.0.10
[INFO] [stderr]    Compiling rayon-core v1.4.0
[INFO] [stderr]    Compiling regex v0.2.10
[INFO] [stderr]    Compiling ucd-util v0.1.1
[INFO] [stderr]    Compiling adler32 v1.0.3
[INFO] [stderr]    Compiling bitflags v1.0.1
[INFO] [stderr]    Compiling itoa v0.4.1
[INFO] [stderr]    Compiling pest v1.0.6
[INFO] [stderr]    Compiling serde v1.0.42
[INFO] [stderr]    Compiling utf8-ranges v1.0.0
[INFO] [stderr]    Compiling cast v0.2.2
[INFO] [stderr]    Compiling dtoa v0.4.2
[INFO] [stderr]    Compiling unicode-width v0.1.4
[INFO] [stderr]    Compiling rustc-demangle v0.1.7
[INFO] [stderr]    Compiling vec_map v0.8.0
[INFO] [stderr]    Compiling color_quant v1.0.1
[INFO] [stderr]    Compiling thread-scoped v1.0.2
[INFO] [stderr]    Compiling quick-error v1.2.1
[INFO] [stderr]    Compiling safemem v0.2.0
[INFO] [stderr]    Compiling proc-macro2 v0.3.6
[INFO] [stderr]    Compiling crossbeam-utils v0.2.2
[INFO] [stderr]    Compiling log v0.4.1
[INFO] [stderr]    Compiling arrayvec v0.4.7
[INFO] [stderr]    Compiling inflate v0.3.4
[INFO] [stderr]    Compiling itertools v0.7.8
[INFO] [stderr]    Compiling regex-syntax v0.5.5
[INFO] [stderr]    Compiling deflate v0.7.18
[INFO] [stderr]    Compiling term v0.5.1
[INFO] [stderr]    Compiling textwrap v0.9.0
[INFO] [stderr]    Compiling syn v0.11.11
[INFO] [stderr]    Compiling thread_local v0.3.5
[INFO] [stderr]    Compiling gif v0.9.2
[INFO] [stderr]    Compiling base64 v0.9.2
[INFO] [stderr]    Compiling num_cpus v1.8.0
[INFO] [stderr]    Compiling rand v0.4.2
[INFO] [stderr]    Compiling memchr v2.0.1
[INFO] [stderr]    Compiling time v0.1.39
[INFO] [stderr]    Compiling atty v0.2.9
[INFO] [stderr]    Compiling crossbeam-epoch v0.3.1
[INFO] [stderr]    Compiling num-integer v0.1.36
[INFO] [stderr]    Compiling num-traits v0.1.43
[INFO] [stderr]    Compiling quote v0.5.2
[INFO] [stderr]    Compiling aho-corasick v0.6.4
[INFO] [stderr]    Compiling clap v2.31.2
[INFO] [stderr]    Compiling itertools-num v0.1.1
[INFO] [stderr]    Compiling enum_primitive v0.1.1
[INFO] [stderr]    Compiling syn v0.13.1
[INFO] [stderr]    Compiling num-iter v0.1.35
[INFO] [stderr]    Compiling chrono v0.4.2
[INFO] [stderr]    Compiling num-rational v0.1.42
[INFO] [stderr]    Compiling crossbeam-deque v0.2.0
[INFO] [stderr]    Compiling criterion-plot v0.2.3
[INFO] [stderr]    Compiling criterion-stats v0.2.3
[INFO] [stderr]    Compiling png v0.11.0
[INFO] [stderr]    Compiling synstructure v0.6.1
[INFO] [stderr]    Compiling backtrace-sys v0.1.16
[INFO] [stderr]    Compiling rayon v1.0.1
[INFO] [stderr]    Compiling simplelog v0.5.1
[INFO] [stderr]    Compiling failure_derive v0.1.1
[INFO] [stderr]    Compiling pest_derive v1.0.7
[INFO] [stderr]    Compiling serde_derive_internals v0.23.1
[INFO] [stderr]    Compiling serde_json v1.0.16
[INFO] [stderr]    Compiling jpeg-decoder v0.1.15
[INFO] [stderr]    Compiling serde_derive v1.0.42
[INFO] [stderr]    Compiling image v0.18.0
[INFO] [stderr]    Compiling handlebars v0.31.0
[INFO] [stderr]    Compiling backtrace v0.3.6
[INFO] [stderr]    Compiling failure v0.1.1
[INFO] [stderr]    Compiling criterion v0.2.3
[INFO] [stderr]    Compiling wu-diff v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> tests/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(extern_prelude)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `extern_prelude` has been stable since 1.30.0 and no longer requires an attribute to enable
[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 `wu-diff` 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" "b12f0b2338d4225b9bddaded3935e6aefc58b4aea15b3eff34eddd4f3f7d5a93", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b12f0b2338d4225b9bddaded3935e6aefc58b4aea15b3eff34eddd4f3f7d5a93", kill_on_drop: false }`
[INFO] [stdout] b12f0b2338d4225b9bddaded3935e6aefc58b4aea15b3eff34eddd4f3f7d5a93