[INFO] fetching crate mathcli 0.1.2...
[INFO] testing mathcli-0.1.2 against 1.54.0 for beta-1.55-1
[INFO] extracting crate mathcli 0.1.2 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate mathcli 0.1.2 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mathcli 0.1.2
[INFO] finished tweaking crates.io crate mathcli 0.1.2
[INFO] tweaked toml for crates.io crate mathcli 0.1.2 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate crates.io crate mathcli 0.1.2 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 00d1f01b3a3362e7389af6fb22ecf2d5acf6697e292679ce376f1af43b842070
[INFO] running `Command { std: "docker" "start" "-a" "00d1f01b3a3362e7389af6fb22ecf2d5acf6697e292679ce376f1af43b842070", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "00d1f01b3a3362e7389af6fb22ecf2d5acf6697e292679ce376f1af43b842070", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "00d1f01b3a3362e7389af6fb22ecf2d5acf6697e292679ce376f1af43b842070", kill_on_drop: false }`
[INFO] [stdout] 00d1f01b3a3362e7389af6fb22ecf2d5acf6697e292679ce376f1af43b842070
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2eeb6feac6b0ec1ddadbbc5bda1a1443b298a455c074c695d8e0b57440467522
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "2eeb6feac6b0ec1ddadbbc5bda1a1443b298a455c074c695d8e0b57440467522", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.20
[INFO] [stderr]    Compiling libc v0.2.76
[INFO] [stderr]    Compiling syn v1.0.39
[INFO] [stderr]    Compiling os_str_bytes v2.3.2
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling hashbrown v0.8.2
[INFO] [stderr]    Compiling indexmap v1.5.2
[INFO] [stderr]    Compiling proc-macro-error-attr v0.4.12
[INFO] [stderr]    Compiling proc-macro-error v0.4.12
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling time v0.1.44
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling chrono v0.4.15
[INFO] [stderr]    Compiling stderrlog v0.5.0
[INFO] [stderr]    Compiling syn-mid v0.5.0
[INFO] [stderr]    Compiling clap_derive v3.0.0-beta.1
[INFO] [stderr]    Compiling clap v3.0.0-beta.1
[INFO] [stderr]    Compiling mathcli v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(iter_map_while, iterator_fold_self, exclusive_range_pattern)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `fold_first` found for opaque type `impl Iterator` in the current scope
[INFO] [stdout]   --> src/main.rs:84:31
[INFO] [stdout]    |
[INFO] [stdout] 84 |         false => parsed_lines.fold_first(|acc, x| operator(acc, x)).unwrap()
[INFO] [stdout]    |                               ^^^^^^^^^^ method not found in `impl Iterator`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0599.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `mathcli`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "2eeb6feac6b0ec1ddadbbc5bda1a1443b298a455c074c695d8e0b57440467522", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2eeb6feac6b0ec1ddadbbc5bda1a1443b298a455c074c695d8e0b57440467522", kill_on_drop: false }`
[INFO] [stdout] 2eeb6feac6b0ec1ddadbbc5bda1a1443b298a455c074c695d8e0b57440467522
