[INFO] fetching crate kstack 0.1.0...
[INFO] testing kstack-0.1.0 against 1.54.0 for beta-1.55-1
[INFO] extracting crate kstack 0.1.0 into /workspace/builds/worker-61/source
[INFO] validating manifest of crates.io crate kstack 0.1.0 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate kstack 0.1.0
[INFO] finished tweaking crates.io crate kstack 0.1.0
[INFO] tweaked toml for crates.io crate kstack 0.1.0 written to /workspace/builds/worker-61/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "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" "+1.54.0" "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-61/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-61/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cc1d6fdbdefcde417d7cdd48b6e83519f5e8df40b46a7eb7b4e6057f3b23c603
[INFO] running `Command { std: "docker" "start" "-a" "cc1d6fdbdefcde417d7cdd48b6e83519f5e8df40b46a7eb7b4e6057f3b23c603", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cc1d6fdbdefcde417d7cdd48b6e83519f5e8df40b46a7eb7b4e6057f3b23c603", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cc1d6fdbdefcde417d7cdd48b6e83519f5e8df40b46a7eb7b4e6057f3b23c603", kill_on_drop: false }`
[INFO] [stdout] cc1d6fdbdefcde417d7cdd48b6e83519f5e8df40b46a7eb7b4e6057f3b23c603
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-61/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-61/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ff7876f475c3d6cfdef051a57f0d9f4ebb1d37d8d0ea0a9a9b1996e86c67187d
[INFO] running `Command { std: "docker" "start" "-a" "ff7876f475c3d6cfdef051a57f0d9f4ebb1d37d8d0ea0a9a9b1996e86c67187d", kill_on_drop: false }`
[INFO] [stderr]    Compiling kstack v0.1.0 (/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_generics)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_generics` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_generics)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]   = note: see issue #44580 <https://github.com/rust-lang/rust/issues/44580> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning 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 `kstack`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "ff7876f475c3d6cfdef051a57f0d9f4ebb1d37d8d0ea0a9a9b1996e86c67187d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ff7876f475c3d6cfdef051a57f0d9f4ebb1d37d8d0ea0a9a9b1996e86c67187d", kill_on_drop: false }`
[INFO] [stdout] ff7876f475c3d6cfdef051a57f0d9f4ebb1d37d8d0ea0a9a9b1996e86c67187d
