[INFO] fetching crate kg-tree 0.2.1...
[INFO] checking kg-tree-0.2.1 against 1.55.0 for beta-1.56-3
[INFO] extracting crate kg-tree 0.2.1 into /workspace/builds/worker-87/source
[INFO] validating manifest of crates.io crate kg-tree 0.2.1 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 kg-tree 0.2.1
[INFO] finished tweaking crates.io crate kg-tree 0.2.1
[INFO] tweaked toml for crates.io crate kg-tree 0.2.1 written to /workspace/builds/worker-87/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-87/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-87/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] 255bc5b7da0f99c8404d100d9005fd383d4a48d410f09dbe555f8ad9e8777c9f
[INFO] running `Command { std: "docker" "start" "-a" "255bc5b7da0f99c8404d100d9005fd383d4a48d410f09dbe555f8ad9e8777c9f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "255bc5b7da0f99c8404d100d9005fd383d4a48d410f09dbe555f8ad9e8777c9f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "255bc5b7da0f99c8404d100d9005fd383d4a48d410f09dbe555f8ad9e8777c9f", kill_on_drop: false }`
[INFO] [stdout] 255bc5b7da0f99c8404d100d9005fd383d4a48d410f09dbe555f8ad9e8777c9f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-87/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-87/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] 612b3d90f38a8ea1de6f99c3b8e3d3f3a65ea9b3651892b856ee3f2edb4d7da9
[INFO] running `Command { std: "docker" "start" "-a" "612b3d90f38a8ea1de6f99c3b8e3d3f3a65ea9b3651892b856ee3f2edb4d7da9", 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] [stderr]    Compiling memchr v2.4.1
[INFO] [stderr]    Compiling serde v1.0.130
[INFO] [stderr]    Compiling heapsize v0.4.2
[INFO] [stderr]    Compiling proc-macro2 v1.0.30
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling static_assertions v1.1.0
[INFO] [stderr]    Compiling arrayvec v0.5.2
[INFO] [stderr]    Compiling cc v1.0.71
[INFO] [stderr]    Compiling syn v1.0.80
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling gimli v0.25.0
[INFO] [stderr]    Compiling parking_lot_core v0.8.5
[INFO] [stderr]    Compiling adler v1.0.2
[INFO] [stderr]    Compiling rustc-demangle v0.1.21
[INFO] [stderr]    Compiling serde_json v1.0.68
[INFO] [stderr]     Checking hashbrown v0.11.2
[INFO] [stderr]     Checking dtoa v0.4.8
[INFO] [stderr]     Checking itoa v0.4.8
[INFO] [stderr]     Checking remove_dir_all v0.5.3
[INFO] [stderr]     Checking assert_approx_eq v1.1.0
[INFO] [stderr]    Compiling nom v5.1.2
[INFO] [stderr]    Compiling indexmap v1.7.0
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling serde_derive v1.0.130
[INFO] [stderr]    Compiling libc v0.2.103
[INFO] [stderr]     Checking lock_api v0.4.5
[INFO] [stderr]     Checking lock_api v0.3.4
[INFO] [stderr]     Checking yaml-rust v0.4.5
[INFO] [stderr]     Checking pretty_assertions v0.6.1
[INFO] [stderr]     Checking lexical-core v0.7.6
[INFO] [stderr]     Checking getrandom v0.2.3
[INFO] [stderr]    Compiling miniz_oxide v0.4.4
[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-0.4.5/src/lib.rs:93:34
[INFO] [stdout]    |
[INFO] [stdout] 93 | #![cfg_attr(feature = "nightly", feature(const_fn_trait_bound))]
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/lock_api-0.3.4/src/lib.rs:91:42
[INFO] [stdout]    |
[INFO] [stdout] 91 | #![cfg_attr(feature = "nightly", feature(const_fn))]
[INFO] [stdout]    |                                          ^^^^^^^^ feature has been removed
[INFO] [stdout]    |
[INFO] [stdout]    = note: split into finer-grained feature gates
[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-0.3.4/src/lib.rs:91:34
[INFO] [stdout]    |
[INFO] [stdout] 91 | #![cfg_attr(feature = "nightly", feature(const_fn))]
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking rand_core v0.6.3
[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 `lock_api` due to 2 previous errors
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] Some errors have detailed explanations: E0554, E0557.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "612b3d90f38a8ea1de6f99c3b8e3d3f3a65ea9b3651892b856ee3f2edb4d7da9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "612b3d90f38a8ea1de6f99c3b8e3d3f3a65ea9b3651892b856ee3f2edb4d7da9", kill_on_drop: false }`
[INFO] [stdout] 612b3d90f38a8ea1de6f99c3b8e3d3f3a65ea9b3651892b856ee3f2edb4d7da9
