[INFO] fetching crate validbr 0.2.1...
[INFO] testing validbr-0.2.1 against 1.55.0 for beta-1.56-1
[INFO] extracting crate validbr 0.2.1 into /workspace/builds/worker-49/source
[INFO] validating manifest of crates.io crate validbr 0.2.1 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 validbr 0.2.1
[INFO] finished tweaking crates.io crate validbr 0.2.1
[INFO] tweaked toml for crates.io crate validbr 0.2.1 written to /workspace/builds/worker-49/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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-49/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-49/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] 96fc8ad91cb46d88120999c90dac5cb1461849fcdba6cbbc389f0a91bed616ae
[INFO] running `Command { std: "docker" "start" "-a" "96fc8ad91cb46d88120999c90dac5cb1461849fcdba6cbbc389f0a91bed616ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "96fc8ad91cb46d88120999c90dac5cb1461849fcdba6cbbc389f0a91bed616ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "96fc8ad91cb46d88120999c90dac5cb1461849fcdba6cbbc389f0a91bed616ae", kill_on_drop: false }`
[INFO] [stdout] 96fc8ad91cb46d88120999c90dac5cb1461849fcdba6cbbc389f0a91bed616ae
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-49/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-49/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] 004dd98c793cff1d729b41f9181833c7e86c59b1069ccd1ec42059822d8dc4dd
[INFO] running `Command { std: "docker" "start" "-a" "004dd98c793cff1d729b41f9181833c7e86c59b1069ccd1ec42059822d8dc4dd", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr]    Compiling validbr v0.2.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:98:1
[INFO] [stdout]    |
[INFO] [stdout] 98 | #![feature(doc_cfg)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:99:1
[INFO] [stdout]    |
[INFO] [stdout] 99 | #![feature(const_evaluatable_checked, const_generics, const_panic)]
[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 `validbr` due to 3 previous errors
[INFO] running `Command { std: "docker" "inspect" "004dd98c793cff1d729b41f9181833c7e86c59b1069ccd1ec42059822d8dc4dd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "004dd98c793cff1d729b41f9181833c7e86c59b1069ccd1ec42059822d8dc4dd", kill_on_drop: false }`
[INFO] [stdout] 004dd98c793cff1d729b41f9181833c7e86c59b1069ccd1ec42059822d8dc4dd