[INFO] fetching crate unwrap_helpers 0.3.0...
[INFO] testing unwrap_helpers-0.3.0 against 1.75.0 for beta-1.76-1
[INFO] extracting crate unwrap_helpers 0.3.0 into /workspace/builds/worker-4-tc1/source
[INFO] validating manifest of crates.io crate unwrap_helpers 0.3.0 on toolchain 1.75.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate unwrap_helpers 0.3.0
[INFO] finished tweaking crates.io crate unwrap_helpers 0.3.0
[INFO] tweaked toml for crates.io crate unwrap_helpers 0.3.0 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded unwrap_helpers_proc_macros v0.1.1
[INFO] [stderr]   Downloaded loop_unwrap v0.2.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d29dba5c5a1aee80b812529fa241dca99cb303583a7d5ffc8834fbac97554cbf
[INFO] running `Command { std: "docker" "start" "-a" "d29dba5c5a1aee80b812529fa241dca99cb303583a7d5ffc8834fbac97554cbf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d29dba5c5a1aee80b812529fa241dca99cb303583a7d5ffc8834fbac97554cbf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d29dba5c5a1aee80b812529fa241dca99cb303583a7d5ffc8834fbac97554cbf", kill_on_drop: false }`
[INFO] [stdout] d29dba5c5a1aee80b812529fa241dca99cb303583a7d5ffc8834fbac97554cbf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ef783809ad85108f545e4ecf71f908e99034dc49b6278d3de18c68c94b5db4a2
[INFO] running `Command { std: "docker" "start" "-a" "ef783809ad85108f545e4ecf71f908e99034dc49b6278d3de18c68c94b5db4a2", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.75
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling loop_unwrap v0.2.0
[INFO] [stderr]    Compiling quote v1.0.35
[INFO] [stderr]    Compiling unwrap_helpers_proc_macros v0.1.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/unwrap_helpers_proc_macros-0.1.1/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(box_patterns)]
[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 `unwrap_helpers_proc_macros` (lib) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "ef783809ad85108f545e4ecf71f908e99034dc49b6278d3de18c68c94b5db4a2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ef783809ad85108f545e4ecf71f908e99034dc49b6278d3de18c68c94b5db4a2", kill_on_drop: false }`
[INFO] [stdout] ef783809ad85108f545e4ecf71f908e99034dc49b6278d3de18c68c94b5db4a2
