[INFO] cloning repository https://github.com/liamzdenek/caption-reading-speed
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/liamzdenek/caption-reading-speed" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fliamzdenek%2Fcaption-reading-speed", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fliamzdenek%2Fcaption-reading-speed'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a84e8e9d30011f974c05356b289bede388dde9b0
[INFO] testing liamzdenek/caption-reading-speed against beta-2021-01-01 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fliamzdenek%2Fcaption-reading-speed" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/liamzdenek/caption-reading-speed 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 git repo https://github.com/liamzdenek/caption-reading-speed
[INFO] finished tweaking git repo https://github.com/liamzdenek/caption-reading-speed
[INFO] tweaked toml for git repo https://github.com/liamzdenek/caption-reading-speed written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/liamzdenek/caption-reading-speed 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 derive_builder v0.7.1
[INFO] [stderr]   Downloaded derive_builder_core v0.4.1
[INFO] [stderr]   Downloaded backtrace v0.3.26
[INFO] [stderr]   Downloaded rustc-demangle v0.1.14
[INFO] [stderr]   Downloaded libc v0.2.55
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6d0fda01862bea2ea089ed88558e4f3dc849ddec517c6981b07c8c126fad01cf
[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" "6d0fda01862bea2ea089ed88558e4f3dc849ddec517c6981b07c8c126fad01cf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6d0fda01862bea2ea089ed88558e4f3dc849ddec517c6981b07c8c126fad01cf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6d0fda01862bea2ea089ed88558e4f3dc849ddec517c6981b07c8c126fad01cf", kill_on_drop: false }`
[INFO] [stdout] 6d0fda01862bea2ea089ed88558e4f3dc849ddec517c6981b07c8c126fad01cf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 711986b16a30759258be6e2133e0e630605f7e84cac3dc98ed11be567e278797
[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" "711986b16a30759258be6e2133e0e630605f7e84cac3dc98ed11be567e278797", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v0.15.34
[INFO] [stderr]    Compiling ident_case v1.0.1
[INFO] [stderr]    Compiling cc v1.0.37
[INFO] [stderr]    Compiling libc v0.2.55
[INFO] [stderr]    Compiling autocfg v0.1.4
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]    Compiling cfg-if v0.1.9
[INFO] [stderr]    Compiling derive_builder v0.7.1
[INFO] [stderr]    Compiling rustc-demangle v0.1.14
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]    Compiling backtrace v0.3.26
[INFO] [stderr]    Compiling backtrace-sys v0.1.28
[INFO] [stderr]    Compiling darling_core v0.8.6
[INFO] [stderr]    Compiling synstructure v0.10.2
[INFO] [stderr]    Compiling darling_macro v0.8.6
[INFO] [stderr]    Compiling failure v0.1.5
[INFO] [stderr]    Compiling darling v0.8.6
[INFO] [stderr]    Compiling derive_builder_core v0.4.1
[INFO] [stderr]    Compiling reading-speed v0.1.0 (/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(duration_float)]
[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 `reading-speed`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "711986b16a30759258be6e2133e0e630605f7e84cac3dc98ed11be567e278797", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "711986b16a30759258be6e2133e0e630605f7e84cac3dc98ed11be567e278797", kill_on_drop: false }`
[INFO] [stdout] 711986b16a30759258be6e2133e0e630605f7e84cac3dc98ed11be567e278797