[INFO] fetching crate casper_event 0.1.0...
[INFO] documenting casper_event-0.1.0 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate casper_event 0.1.0 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate casper_event 0.1.0 on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-2/source/.cargo/config.toml
[INFO] started tweaking crates.io crate casper_event 0.1.0
[INFO] finished tweaking crates.io crate casper_event 0.1.0
[INFO] tweaked toml for crates.io crate casper_event 0.1.0 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded casper-contract v1.4.4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 728c74adfb1f4fd052f5551d8999755f8622571547c5442de2f923c4e9825ec7
[INFO] running `Command { std: "docker" "start" "-a" "728c74adfb1f4fd052f5551d8999755f8622571547c5442de2f923c4e9825ec7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "728c74adfb1f4fd052f5551d8999755f8622571547c5442de2f923c4e9825ec7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "728c74adfb1f4fd052f5551d8999755f8622571547c5442de2f923c4e9825ec7", kill_on_drop: false }`
[INFO] [stdout] 728c74adfb1f4fd052f5551d8999755f8622571547c5442de2f923c4e9825ec7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "RUSTDOCFLAGS=--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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a47c263c07f42f1f36a7b416e770987e178870d34db9d503a1c6f7ea598aa96f
[INFO] running `Command { std: "docker" "start" "-a" "a47c263c07f42f1f36a7b416e770987e178870d34db9d503a1c6f7ea598aa96f", kill_on_drop: false }`
[INFO] [stderr]    Compiling version_check v0.9.4
[INFO] [stderr]    Compiling typenum v1.15.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.39
[INFO] [stderr]    Compiling autocfg v1.1.0
[INFO] [stderr]    Compiling unicode-ident v1.0.0
[INFO] [stderr]    Compiling syn v1.0.95
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking subtle v2.4.1
[INFO] [stderr]    Compiling unicode-xid v0.2.3
[INFO] [stderr]     Checking radium v0.3.0
[INFO] [stderr]     Checking funty v1.1.0
[INFO] [stderr]     Checking wyz v0.2.0
[INFO] [stderr]    Compiling serde_derive v1.0.137
[INFO] [stderr]    Compiling serde v1.0.137
[INFO] [stderr]     Checking ppv-lite86 v0.2.16
[INFO] [stderr]    Compiling crunchy v0.2.2
[INFO] [stderr]     Checking byteorder v1.4.3
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking opaque-debug v0.3.0
[INFO] [stderr]    Compiling serde_json v1.0.81
[INFO] [stderr]    Compiling libc v0.2.126
[INFO] [stderr]     Checking cpufeatures v0.2.2
[INFO] [stderr]     Checking ryu v1.0.10
[INFO] [stderr]     Checking static_assertions v1.1.0
[INFO] [stderr]     Checking rand_core v0.6.3
[INFO] [stderr]     Checking hex v0.4.3
[INFO] [stderr]    Compiling wee_alloc v0.4.5
[INFO] [stderr]     Checking itoa v1.0.2
[INFO] [stderr]     Checking hex_fmt v0.3.0
[INFO] [stderr]     Checking memory_units v0.4.0
[INFO] [stderr]     Checking bitflags v1.3.2
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking base16 v0.2.1
[INFO] [stderr]     Checking base64 v0.13.0
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking bitvec v0.18.5
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling num-integer v0.1.45
[INFO] [stderr]    Compiling num-bigint v0.4.3
[INFO] [stderr]    Compiling num-rational v0.4.0
[INFO] [stderr]    Compiling num-iter v0.1.43
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]    Compiling generic-array v0.14.5
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking uint v0.9.3
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stderr]     Checking ff v0.8.0
[INFO] [stderr]     Checking group v0.8.0
[INFO] [stderr]     Checking digest v0.9.0
[INFO] [stderr]     Checking crypto-mac v0.10.1
[INFO] [stderr]     Checking block-buffer v0.9.0
[INFO] [stderr]     Checking crypto-mac v0.8.0
[INFO] [stderr]     Checking signature v1.2.2
[INFO] [stderr]     Checking hmac v0.10.1
[INFO] [stderr]     Checking sha2 v0.9.9
[INFO] [stderr]     Checking blake2 v0.9.2
[INFO] [stderr]     Checking num-complex v0.4.1
[INFO] [stderr]     Checking ed25519 v1.2.0
[INFO] [stderr]    Compiling synstructure v0.12.6
[INFO] [stderr]     Checking num v0.4.0
[INFO] [stderr]    Compiling zeroize_derive v1.3.2
[INFO] [stderr]    Compiling num-derive v0.3.3
[INFO] [stderr]     Checking zeroize v1.3.0
[INFO] [stderr]     Checking elliptic-curve v0.8.5
[INFO] [stderr]     Checking curve25519-dalek v3.2.1
[INFO] [stderr]     Checking ecdsa v0.10.2
[INFO] [stderr]     Checking ed25519-dalek v1.0.1
[INFO] [stderr]     Checking k256 v0.7.3
[INFO] [stderr]     Checking serde_bytes v0.11.6
[INFO] [stderr]     Checking casper-types v1.5.0
[INFO] [stderr]     Checking casper-contract v1.4.4
[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/casper-contract-1.4.4/src/lib.rs:51:5
[INFO] [stdout]    |
[INFO] [stdout] 51 |     feature(alloc_error_handler, core_intrinsics, lang_items)
[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/casper-contract-1.4.4/src/lib.rs:51:34
[INFO] [stdout]    |
[INFO] [stdout] 51 |     feature(alloc_error_handler, core_intrinsics, lang_items)
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[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: could not compile `casper-contract` due to 3 previous errors
[INFO] running `Command { std: "docker" "inspect" "a47c263c07f42f1f36a7b416e770987e178870d34db9d503a1c6f7ea598aa96f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a47c263c07f42f1f36a7b416e770987e178870d34db9d503a1c6f7ea598aa96f", kill_on_drop: false }`
[INFO] [stdout] a47c263c07f42f1f36a7b416e770987e178870d34db9d503a1c6f7ea598aa96f