[INFO] updating cached repository https://github.com/mwdowns/rust_matt_os
[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] 8be087538b6e755d725d7f790c3696a14d08456a
[INFO] checking mwdowns/rust_matt_os against master#8ac1525e091d3db28e67adcbbd6db1e1deaa37fb for pr-73323
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmwdowns%2Frust_matt_os" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mwdowns/rust_matt_os on toolchain 8ac1525e091d3db28e67adcbbd6db1e1deaa37fb
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8ac1525e091d3db28e67adcbbd6db1e1deaa37fb" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/mwdowns/rust_matt_os
[INFO] finished tweaking git repo https://github.com/mwdowns/rust_matt_os
[INFO] tweaked toml for git repo https://github.com/mwdowns/rust_matt_os written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/mwdowns/rust_matt_os already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8ac1525e091d3db28e67adcbbd6db1e1deaa37fb" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+8ac1525e091d3db28e67adcbbd6db1e1deaa37fb" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2b4e47c8bb1364ff2dff90202d8157b15786c71b776f7e3f17daae3a7fb9db1f
[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" "2b4e47c8bb1364ff2dff90202d8157b15786c71b776f7e3f17daae3a7fb9db1f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2b4e47c8bb1364ff2dff90202d8157b15786c71b776f7e3f17daae3a7fb9db1f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2b4e47c8bb1364ff2dff90202d8157b15786c71b776f7e3f17daae3a7fb9db1f", kill_on_drop: false }`
[INFO] [stdout] 2b4e47c8bb1364ff2dff90202d8157b15786c71b776f7e3f17daae3a7fb9db1f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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=forbid" "-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@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+8ac1525e091d3db28e67adcbbd6db1e1deaa37fb" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] abefd4a1b9d3860c6ddb3a95b9cd1af300a69ba29f8a3fe2d6591293e91fb251
[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" "abefd4a1b9d3860c6ddb3a95b9cd1af300a69ba29f8a3fe2d6591293e91fb251", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking matt_os v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0522]: definition of an unknown language item: `panic_fmt`
[INFO] [stdout]  --> src/main.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #[lang = "panic_fmt"]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^ definition of unknown language item `panic_fmt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: `#[panic_handler]` function required, but not found
[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 E0522`.
[INFO] [stdout] 
[INFO] [stdout] error[E0522]: definition of an unknown language item: `panic_fmt`
[INFO] [stdout]  --> src/main.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #[lang = "panic_fmt"]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^ definition of unknown language item `panic_fmt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `matt_os`.
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0522`.
[INFO] [stdout] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "abefd4a1b9d3860c6ddb3a95b9cd1af300a69ba29f8a3fe2d6591293e91fb251", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "abefd4a1b9d3860c6ddb3a95b9cd1af300a69ba29f8a3fe2d6591293e91fb251", kill_on_drop: false }`
[INFO] [stdout] abefd4a1b9d3860c6ddb3a95b9cd1af300a69ba29f8a3fe2d6591293e91fb251