[INFO] fetching crate indexkv 0.2.9...
[INFO] testing indexkv-0.2.9 against 1.55.0 for beta-1.56-1
[INFO] extracting crate indexkv 0.2.9 into /workspace/builds/worker-62/source
[INFO] validating manifest of crates.io crate indexkv 0.2.9 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 indexkv 0.2.9
[INFO] finished tweaking crates.io crate indexkv 0.2.9
[INFO] tweaked toml for crates.io crate indexkv 0.2.9 written to /workspace/builds/worker-62/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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded english-numbers v0.3.3
[INFO] [stderr]   Downloaded async-bincode v0.5.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-62/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-62/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] a8c173562b16493ee167912e15c1096a184f730977bafe0c1d988c16a46f322d
[INFO] running `Command { std: "docker" "start" "-a" "a8c173562b16493ee167912e15c1096a184f730977bafe0c1d988c16a46f322d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a8c173562b16493ee167912e15c1096a184f730977bafe0c1d988c16a46f322d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a8c173562b16493ee167912e15c1096a184f730977bafe0c1d988c16a46f322d", kill_on_drop: false }`
[INFO] [stdout] a8c173562b16493ee167912e15c1096a184f730977bafe0c1d988c16a46f322d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-62/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-62/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] 29f96c3aeba8e52037e86b679d9b770a573ed018585c72faecdb25c13099aa35
[INFO] running `Command { std: "docker" "start" "-a" "29f96c3aeba8e52037e86b679d9b770a573ed018585c72faecdb25c13099aa35", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling proc-macro-nested v0.1.7
[INFO] [stderr]    Compiling futures-channel v0.3.17
[INFO] [stderr]    Compiling futures-macro v0.3.17
[INFO] [stderr]    Compiling futures-util v0.3.17
[INFO] [stderr]    Compiling mio v0.6.23
[INFO] [stderr]    Compiling tokio-macros v0.2.6
[INFO] [stderr]    Compiling thiserror-impl v1.0.29
[INFO] [stderr]    Compiling bincode v1.3.3
[INFO] [stderr]    Compiling tokio v0.2.25
[INFO] [stderr]    Compiling thiserror v1.0.29
[INFO] [stderr]    Compiling async-bincode v0.5.1
[INFO] [stderr]    Compiling futures-executor v0.3.17
[INFO] [stderr]    Compiling futures v0.3.17
[INFO] [stderr]    Compiling indexkv v0.2.9 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn_trait_bound)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: cannot use constants which depend on generic parameters in types
[INFO] [stdout]    --> src/lib.rs:110:23
[INFO] [stdout]     |
[INFO] [stdout] 110 |         let mut buf = [0u8; Self::header_size() as usize];
[INFO] [stdout]     |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(const_evaluatable_unchecked)]` on by default
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = note: for more information, see issue #76200 <https://github.com/rust-lang/rust/issues/76200>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: cannot use constants which depend on generic parameters in types
[INFO] [stdout]    --> src/lib.rs:118:23
[INFO] [stdout]     |
[INFO] [stdout] 118 |         let mut buf = [0u8; Self::index_entry_size() as usize];
[INFO] [stdout]     |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = note: for more information, see issue #76200 <https://github.com/rust-lang/rust/issues/76200>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `indexkv` due to 2 previous errors; 2 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "29f96c3aeba8e52037e86b679d9b770a573ed018585c72faecdb25c13099aa35", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "29f96c3aeba8e52037e86b679d9b770a573ed018585c72faecdb25c13099aa35", kill_on_drop: false }`
[INFO] [stdout] 29f96c3aeba8e52037e86b679d9b770a573ed018585c72faecdb25c13099aa35