[INFO] updating cached repository https://github.com/dcampbell24/rusty_skyscrapers
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c65709e1cc3a53b6788ca3abb530b10c9a7d4018
[INFO] testing dcampbell24/rusty_skyscrapers against beta-2020-07-24 for beta-1.46-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdcampbell24%2Frusty_skyscrapers" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dcampbell24/rusty_skyscrapers on toolchain beta-2020-07-24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/dcampbell24/rusty_skyscrapers
[INFO] finished tweaking git repo https://github.com/dcampbell24/rusty_skyscrapers
[INFO] tweaked toml for git repo https://github.com/dcampbell24/rusty_skyscrapers written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/dcampbell24/rusty_skyscrapers already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] error: the lock file /workspace/builds/worker-7/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1b3f9b4951118606002741e0d1e6bbe39d8bb89fc6b981b38552343dbfe8f509
[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" "1b3f9b4951118606002741e0d1e6bbe39d8bb89fc6b981b38552343dbfe8f509", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1b3f9b4951118606002741e0d1e6bbe39d8bb89fc6b981b38552343dbfe8f509", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1b3f9b4951118606002741e0d1e6bbe39d8bb89fc6b981b38552343dbfe8f509", kill_on_drop: false }`
[INFO] [stdout] 1b3f9b4951118606002741e0d1e6bbe39d8bb89fc6b981b38552343dbfe8f509
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8cea09991faf1d02c1657f374435fdab26bc844e2b016f173e3b7cad9e35d747
[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" "8cea09991faf1d02c1657f374435fdab26bc844e2b016f173e3b7cad9e35d747", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.74
[INFO] [stderr]    Compiling serde v1.0.114
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.2
[INFO] [stderr]    Compiling rand v0.7.3
[INFO] [stderr]    Compiling docopt v1.1.0
[INFO] [stderr]    Compiling rusty_skyscrapers v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0599]: no method named `decode` found for struct `docopt::Docopt` in the current scope
[INFO] [stdout]   --> src/main.rs:79:56
[INFO] [stdout]    |
[INFO] [stdout] 79 |     let args: Args = Docopt::new(USAGE).and_then(|d| d.decode()).unwrap_or_else(|e| {
[INFO] [stdout]    |                                                        ^^^^^^ method not found in `docopt::Docopt`
[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 E0599`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rusty_skyscrapers`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "8cea09991faf1d02c1657f374435fdab26bc844e2b016f173e3b7cad9e35d747", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8cea09991faf1d02c1657f374435fdab26bc844e2b016f173e3b7cad9e35d747", kill_on_drop: false }`
[INFO] [stdout] 8cea09991faf1d02c1657f374435fdab26bc844e2b016f173e3b7cad9e35d747