[INFO] cloning repository https://github.com/coltonweaver/rust-os-tutorial
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/coltonweaver/rust-os-tutorial" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcoltonweaver%2Frust-os-tutorial", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcoltonweaver%2Frust-os-tutorial'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d9745ed067f78188b976b9937dc4556877d80d6a
[INFO] checking coltonweaver/rust-os-tutorial against try#575650af7d7ca88602df28e39d27bf3e456c306e for pr-80579
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcoltonweaver%2Frust-os-tutorial" "/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/coltonweaver/rust-os-tutorial on toolchain 575650af7d7ca88602df28e39d27bf3e456c306e
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+575650af7d7ca88602df28e39d27bf3e456c306e" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-3/source/.cargo/config
[INFO] started tweaking git repo https://github.com/coltonweaver/rust-os-tutorial
[INFO] removed 0 missing tests
[INFO] finished tweaking git repo https://github.com/coltonweaver/rust-os-tutorial
[INFO] tweaked toml for git repo https://github.com/coltonweaver/rust-os-tutorial written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/coltonweaver/rust-os-tutorial already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+575650af7d7ca88602df28e39d27bf3e456c306e" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded spinning_top v0.1.0
[INFO] [stderr]   Downloaded linked_list_allocator v0.8.4
[INFO] [stderr]   Downloaded pc-keyboard v0.5.0
[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" "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" "+575650af7d7ca88602df28e39d27bf3e456c306e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2d58e0fde94ce6ce28151c1f939572d6b17f12ba57ff8deb9c2db465fc7a88fc
[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" "2d58e0fde94ce6ce28151c1f939572d6b17f12ba57ff8deb9c2db465fc7a88fc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2d58e0fde94ce6ce28151c1f939572d6b17f12ba57ff8deb9c2db465fc7a88fc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2d58e0fde94ce6ce28151c1f939572d6b17f12ba57ff8deb9c2db465fc7a88fc", kill_on_drop: false }`
[INFO] [stdout] 2d58e0fde94ce6ce28151c1f939572d6b17f12ba57ff8deb9c2db465fc7a88fc
[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" "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" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+575650af7d7ca88602df28e39d27bf3e456c306e" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b8924cf61fe9ea3707c7179edcada087e1829151c149aea291905014bba0d1e1
[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" "b8924cf61fe9ea3707c7179edcada087e1829151c149aea291905014bba0d1e1", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.19
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.36
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling autocfg v1.0.0
[INFO] [stderr]    Compiling pin-project-internal v0.4.23
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling x86_64 v0.11.0
[INFO] [stderr]    Compiling bootloader v0.9.4
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]     Checking bit_field v0.9.0
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking cpuio v0.3.0
[INFO] [stderr]     Checking futures-core v0.3.5
[INFO] [stderr]     Checking conquer-util v0.2.0
[INFO] [stderr]     Checking futures-task v0.3.5
[INFO] [stderr]     Checking spin v0.5.2
[INFO] [stderr]     Checking pc-keyboard v0.5.0
[INFO] [stderr]     Checking pin-utils v0.1.0
[INFO] [stderr]     Checking volatile v0.2.6
[INFO] [stderr]     Checking pic8259_simple v0.2.0
[INFO] [stderr]     Checking conquer-once v0.2.1
[INFO] [stderr]     Checking lock_api v0.3.4
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking spinning_top v0.1.0
[INFO] [stderr]     Checking linked_list_allocator v0.8.4
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stdout] error[E0658]: mutable references are not allowed in constant functions
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/linked_list_allocator-0.8.4/src/hole.rs:18:23
[INFO] [stdout]    |
[INFO] [stdout] 18 |                 next: None,
[INFO] [stdout]    |                       ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #57349 <https://github.com/rust-lang/rust/issues/57349> for more information
[INFO] [stdout]    = help: add `#![feature(const_mut_refs)]` to the crate attributes to enable
[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 E0658`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `linked_list_allocator`
[INFO] [stderr] 
[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" "b8924cf61fe9ea3707c7179edcada087e1829151c149aea291905014bba0d1e1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b8924cf61fe9ea3707c7179edcada087e1829151c149aea291905014bba0d1e1", kill_on_drop: false }`
[INFO] [stdout] b8924cf61fe9ea3707c7179edcada087e1829151c149aea291905014bba0d1e1