[INFO] fetching crate rustc-ap-rustc_session 727.0.0...
[INFO] testing rustc-ap-rustc_session-727.0.0 against 1.55.0 for beta-1.56-1
[INFO] extracting crate rustc-ap-rustc_session 727.0.0 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate rustc-ap-rustc_session 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_session 727.0.0
[INFO] finished tweaking crates.io crate rustc-ap-rustc_session 727.0.0
[INFO] tweaked toml for crates.io crate rustc-ap-rustc_session 727.0.0 written to /workspace/builds/worker-7/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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rustc-ap-rustc_lint_defs v727.0.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_feature v727.0.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_target v727.0.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_ast v727.0.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_fs_util v727.0.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_errors v727.0.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_lexer v727.0.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 68bed2fbd0067a40ccec4859c735a3382938af5999d50a98598047cf7ea3a020
[INFO] running `Command { std: "docker" "start" "-a" "68bed2fbd0067a40ccec4859c735a3382938af5999d50a98598047cf7ea3a020", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "68bed2fbd0067a40ccec4859c735a3382938af5999d50a98598047cf7ea3a020", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "68bed2fbd0067a40ccec4859c735a3382938af5999d50a98598047cf7ea3a020", kill_on_drop: false }`
[INFO] [stdout] 68bed2fbd0067a40ccec4859c735a3382938af5999d50a98598047cf7ea3a020
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] a7df9040a7bc6b7344c317c04802e1109227b807b8556b5efbc0e1f890419ac2
[INFO] running `Command { std: "docker" "start" "-a" "a7df9040a7bc6b7344c317c04802e1109227b807b8556b5efbc0e1f890419ac2", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.76
[INFO] [stderr]    Compiling smallvec v1.6.1
[INFO] [stderr]    Compiling hashbrown v0.11.2
[INFO] [stderr]    Compiling rustc-rayon-core v0.3.1
[INFO] [stderr]    Compiling rustc-hash v1.1.0
[INFO] [stderr]    Compiling arrayvec v0.7.1
[INFO] [stderr]    Compiling opaque-debug v0.3.0
[INFO] [stderr]    Compiling rustc-ap-rustc_graphviz v727.0.0
[INFO] [stderr]    Compiling cpufeatures v0.2.1
[INFO] [stderr]    Compiling scoped-tls v1.0.0
[INFO] [stderr]    Compiling annotate-snippets v0.8.0
[INFO] [stderr]    Compiling termcolor v1.1.2
[INFO] [stderr]    Compiling rustc-ap-rustc_fs_util v727.0.0
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling memoffset v0.5.6
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling indexmap v1.7.0
[INFO] [stderr]    Compiling psm v0.1.16
[INFO] [stderr]    Compiling stacker v0.1.14
[INFO] [stderr]    Compiling tracing-core v0.1.19
[INFO] [stderr]    Compiling rustc-ap-rustc_lexer v727.0.0
[INFO] [stderr]    Compiling memmap2 v0.2.3
[INFO] [stderr]    Compiling perf-event-open-sys v1.0.1
[INFO] [stderr]    Compiling ena v0.14.0
[INFO] [stderr]    Compiling jobserver v0.1.24
[INFO] [stderr]    Compiling termize v0.1.1
[INFO] [stderr]    Compiling block-buffer v0.9.0
[INFO] [stderr]    Compiling digest v0.9.0
[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] [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] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "a7df9040a7bc6b7344c317c04802e1109227b807b8556b5efbc0e1f890419ac2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a7df9040a7bc6b7344c317c04802e1109227b807b8556b5efbc0e1f890419ac2", kill_on_drop: false }`
[INFO] [stdout] a7df9040a7bc6b7344c317c04802e1109227b807b8556b5efbc0e1f890419ac2