[INFO] cloning repository https://github.com/nelhage/ultimattt
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/nelhage/ultimattt" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnelhage%2Fultimattt", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnelhage%2Fultimattt'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f50df2cd672dfca80b5164d535dc3adb34f887cd
[INFO] testing nelhage/ultimattt against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnelhage%2Fultimattt" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/nelhage/ultimattt 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 git repo https://github.com/nelhage/ultimattt
[INFO] finished tweaking git repo https://github.com/nelhage/ultimattt
[INFO] tweaked toml for git repo https://github.com/nelhage/ultimattt written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/nelhage/ultimattt 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] 8fb7e45a306b305fd5871f5491a7af8cf9fc5012bea2241dfd7ffab3ca65d5ad
[INFO] running `Command { std: "docker" "start" "-a" "8fb7e45a306b305fd5871f5491a7af8cf9fc5012bea2241dfd7ffab3ca65d5ad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8fb7e45a306b305fd5871f5491a7af8cf9fc5012bea2241dfd7ffab3ca65d5ad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8fb7e45a306b305fd5871f5491a7af8cf9fc5012bea2241dfd7ffab3ca65d5ad", kill_on_drop: false }`
[INFO] [stdout] 8fb7e45a306b305fd5871f5491a7af8cf9fc5012bea2241dfd7ffab3ca65d5ad
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] 2d99563b9a7a374d9a20c451628963f65998bf03755bc55be275d30e75c57a21
[INFO] running `Command { std: "docker" "start" "-a" "2d99563b9a7a374d9a20c451628963f65998bf03755bc55be275d30e75c57a21", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.73
[INFO] [stderr]    Compiling semver v1.0.3
[INFO] [stderr]    Compiling serde_derive v1.0.126
[INFO] [stderr]    Compiling serde v1.0.126
[INFO] [stderr]    Compiling packed_simd_2 v0.3.5
[INFO] [stderr]    Compiling bytesize v1.0.1
[INFO] [stderr]    Compiling probe v0.2.1 (https://github.com/cuviper/rust-libprobe.git#ae1286b2)
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling nom v6.1.2
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]    Compiling time v0.1.44
[INFO] [stderr]    Compiling getrandom v0.1.16
[INFO] [stderr]    Compiling parking_lot_core v0.7.2
[INFO] [stderr]    Compiling flate2 v1.0.20
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/git/checkouts/rust-libprobe-428800595a569dcb/ae1286b/src/lib.rs:99:1
[INFO] [stdout]    |
[INFO] [stdout] 99 | #![feature(asm)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^
[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 `probe` 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" "2d99563b9a7a374d9a20c451628963f65998bf03755bc55be275d30e75c57a21", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2d99563b9a7a374d9a20c451628963f65998bf03755bc55be275d30e75c57a21", kill_on_drop: false }`
[INFO] [stdout] 2d99563b9a7a374d9a20c451628963f65998bf03755bc55be275d30e75c57a21