[INFO] fetching crate tuifw 0.0.6...
[INFO] testing tuifw-0.0.6 against 1.55.0 for beta-1.56-1
[INFO] extracting crate tuifw 0.0.6 into /workspace/builds/worker-72/source
[INFO] validating manifest of crates.io crate tuifw 0.0.6 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 tuifw 0.0.6
[INFO] finished tweaking crates.io crate tuifw 0.0.6
[INFO] tweaked toml for crates.io crate tuifw 0.0.6 written to /workspace/builds/worker-72/source/Cargo.toml
[INFO] crate crates.io crate tuifw 0.0.6 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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded debug_panic v0.2.1
[INFO] [stderr]   Downloaded dep-obj v0.27.1
[INFO] [stderr]   Downloaded tuifw-window v0.9.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-72/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-72/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] 52efbbf2a995c6889edf70e6520467b3d0ff1ff02f49b48d284f16c169acf31a
[INFO] running `Command { std: "docker" "start" "-a" "52efbbf2a995c6889edf70e6520467b3d0ff1ff02f49b48d284f16c169acf31a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "52efbbf2a995c6889edf70e6520467b3d0ff1ff02f49b48d284f16c169acf31a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "52efbbf2a995c6889edf70e6520467b3d0ff1ff02f49b48d284f16c169acf31a", kill_on_drop: false }`
[INFO] [stdout] 52efbbf2a995c6889edf70e6520467b3d0ff1ff02f49b48d284f16c169acf31a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-72/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-72/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] 272c7e8c4291e463474d39d97cf903d226694f6717c2b4ec4353c12ec7ac8195
[INFO] running `Command { std: "docker" "start" "-a" "272c7e8c4291e463474d39d97cf903d226694f6717c2b4ec4353c12ec7ac8195", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.27
[INFO] [stderr]    Compiling syn v1.0.73
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling generics v0.3.2
[INFO] [stderr]    Compiling paste v1.0.5
[INFO] [stderr]    Compiling macro-attr-2018 v1.1.1
[INFO] [stderr]    Compiling panicking v0.0.1
[INFO] [stderr]    Compiling bitflags v1.3.2
[INFO] [stderr]    Compiling enum-derive-2018 v1.0.2
[INFO] [stderr]    Compiling downcast-rs v1.2.0
[INFO] [stderr]    Compiling debug_panic v0.2.1
[INFO] [stderr]    Compiling num-bigint v0.4.0
[INFO] [stderr]    Compiling memoffset v0.6.4
[INFO] [stderr]    Compiling tuifw-screen-base v0.9.0
[INFO] [stderr]    Compiling rand v0.8.4
[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/tuifw-screen-base-0.9.0/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_panic)]
[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/tuifw-screen-base-0.9.0/src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(stmt_expr_attributes)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `tuifw-screen-base` due to 3 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "272c7e8c4291e463474d39d97cf903d226694f6717c2b4ec4353c12ec7ac8195", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "272c7e8c4291e463474d39d97cf903d226694f6717c2b4ec4353c12ec7ac8195", kill_on_drop: false }`
[INFO] [stdout] 272c7e8c4291e463474d39d97cf903d226694f6717c2b4ec4353c12ec7ac8195