[INFO] fetching crate mathcli 0.1.2...
[INFO] testing mathcli-0.1.2 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate mathcli 0.1.2 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate mathcli 0.1.2 on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", 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-8/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" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded strsim v0.10.0
[INFO] [stderr]   Downloaded indexmap v1.5.2
[INFO] [stderr]   Downloaded os_str_bytes v2.3.2
[INFO] [stderr]   Downloaded clap_derive v3.0.0-beta.1
[INFO] [stderr]   Downloaded stderrlog v0.5.0
[INFO] [stderr]   Downloaded clap v3.0.0-beta.1
[INFO] [stderr]   Downloaded proc-macro-error v0.4.12
[INFO] [stderr]   Downloaded proc-macro-error-attr v0.4.12
[INFO] [stderr]   Downloaded chrono v0.4.15
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 91f49d3a8bd306b7b547715218927c7e4a5a30b826a43ce110b665a015cbda4e
[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" "91f49d3a8bd306b7b547715218927c7e4a5a30b826a43ce110b665a015cbda4e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "91f49d3a8bd306b7b547715218927c7e4a5a30b826a43ce110b665a015cbda4e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "91f49d3a8bd306b7b547715218927c7e4a5a30b826a43ce110b665a015cbda4e", kill_on_drop: false }`
[INFO] [stdout] 91f49d3a8bd306b7b547715218927c7e4a5a30b826a43ce110b665a015cbda4e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3c5af72f4af482e1f2b2b56aa915f5a9d3a3f7c94098d2f04fd9f0f782d6b169
[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" "3c5af72f4af482e1f2b2b56aa915f5a9d3a3f7c94098d2f04fd9f0f782d6b169", 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 strsim v0.10.0
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling num-integer v0.1.43
[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 quote v1.0.7
[INFO] [stderr]    Compiling time v0.1.44
[INFO] [stderr]    Compiling atty v0.2.14
[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 beta 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: 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 `mathcli`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "3c5af72f4af482e1f2b2b56aa915f5a9d3a3f7c94098d2f04fd9f0f782d6b169", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3c5af72f4af482e1f2b2b56aa915f5a9d3a3f7c94098d2f04fd9f0f782d6b169", kill_on_drop: false }`
[INFO] [stdout] 3c5af72f4af482e1f2b2b56aa915f5a9d3a3f7c94098d2f04fd9f0f782d6b169