[INFO] fetching crate rustc-ap-rustc_attr 727.0.0...
[INFO] testing rustc-ap-rustc_attr-727.0.0 against 1.55.0 for beta-1.56-1
[INFO] extracting crate rustc-ap-rustc_attr 727.0.0 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate rustc-ap-rustc_attr 727.0.0 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 rustc-ap-rustc_attr 727.0.0
[INFO] finished tweaking crates.io crate rustc-ap-rustc_attr 727.0.0
[INFO] tweaked toml for crates.io crate rustc-ap-rustc_attr 727.0.0 written to /workspace/builds/worker-5/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] 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] 828d8b6d7e0604182de515e25889a5a09c7fed05efeed329b0d10fc90cfc2986
[INFO] running `Command { std: "docker" "start" "-a" "828d8b6d7e0604182de515e25889a5a09c7fed05efeed329b0d10fc90cfc2986", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "828d8b6d7e0604182de515e25889a5a09c7fed05efeed329b0d10fc90cfc2986", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "828d8b6d7e0604182de515e25889a5a09c7fed05efeed329b0d10fc90cfc2986", kill_on_drop: false }`
[INFO] [stdout] 828d8b6d7e0604182de515e25889a5a09c7fed05efeed329b0d10fc90cfc2986
[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] 8408fe808b7a55f352c407da6b413de1327fbb1d8f4da392a6d468999a21143a
[INFO] running `Command { std: "docker" "start" "-a" "8408fe808b7a55f352c407da6b413de1327fbb1d8f4da392a6d468999a21143a", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling smallvec v1.6.1
[INFO] [stderr]    Compiling rustc-ap-rustc_graphviz v727.0.0
[INFO] [stderr]    Compiling annotate-snippets v0.8.0
[INFO] [stderr]    Compiling rustc-ap-rustc_fs_util v727.0.0
[INFO] [stderr]    Compiling typenum v1.14.0
[INFO] [stderr]    Compiling rustc-ap-rustc_lexer v727.0.0
[INFO] [stderr]    Compiling generic-array v0.14.4
[INFO] [stderr]    Compiling termize v0.1.1
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling crossbeam-queue v0.2.3
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rustc-ap-rustc_macros v727.0.0
[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/smallvec-1.6.1/src/lib.rs:76:37
[INFO] [stdout]    |
[INFO] [stdout] 76 | #![cfg_attr(feature = "may_dangle", feature(dropck_eyepatch))]
[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/rustc-ap-rustc_graphviz-727.0.0/src/lib.rs:278:1
[INFO] [stdout]     |
[INFO] [stdout] 278 | #![feature(nll)]
[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 `smallvec` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[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] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/rustc-ap-rustc_macros-727.0.0/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro_diagnostic)]
[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: build failed
[INFO] running `Command { std: "docker" "inspect" "8408fe808b7a55f352c407da6b413de1327fbb1d8f4da392a6d468999a21143a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8408fe808b7a55f352c407da6b413de1327fbb1d8f4da392a6d468999a21143a", kill_on_drop: false }`
[INFO] [stdout] 8408fe808b7a55f352c407da6b413de1327fbb1d8f4da392a6d468999a21143a