[INFO] updating cached repository https://github.com/alex-karo/rust-test
[INFO] running `"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"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 709e5574836ec13f469365d8c66dea2336c80732
[INFO] testing alex-karo/rust-test against 1.44.0 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falex-karo%2Frust-test" "/workspace/builds/worker-6/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/alex-karo/rust-test on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/alex-karo/rust-test
[INFO] finished tweaking git repo https://github.com/alex-karo/rust-test
[INFO] tweaked toml for git repo https://github.com/alex-karo/rust-test written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/alex-karo/rust-test already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "/opt/rustwide/cargo-home/bin/cargo" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 293bcfc549a1310c1d13923ab2eba259afbf38d933032f4fefe5c06d140d7176
[INFO] running `"docker" "start" "-a" "293bcfc549a1310c1d13923ab2eba259afbf38d933032f4fefe5c06d140d7176"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling rust-test v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0308]: mismatched types
[INFO] [stderr]   --> src/main.rs:70:27
[INFO] [stderr]    |
[INFO] [stderr] 70 |               Some(node) => {
[INFO] [stderr]    |  ___________________________^
[INFO] [stderr] 71 | |
[INFO] [stderr] 72 | |             },
[INFO] [stderr]    | |_____________^ expected enum `std::option::Option`, found `()`
[INFO] [stderr]    |
[INFO] [stderr]    = note:   expected enum `std::option::Option<T>`
[INFO] [stderr]            found unit type `()`
[INFO] [stderr] 
[INFO] [stderr] error[E0308]: mismatched types
[INFO] [stderr]   --> src/main.rs:74:29
[INFO] [stderr]    |
[INFO] [stderr] 74 |                 self.curr = &self.head;
[INFO] [stderr]    |                             ^^^^^^^^^^
[INFO] [stderr]    |                             |
[INFO] [stderr]    |                             expected enum `std::option::Option`, found reference
[INFO] [stderr]    |                             help: consider removing the borrow: `self.head`
[INFO] [stderr]    |
[INFO] [stderr]    = note:   expected enum `std::option::Option<std::boxed::Box<Node<T>>>`
[INFO] [stderr]            found reference `&std::option::Option<std::boxed::Box<Node<T>>>`
[INFO] [stderr] 
[INFO] [stderr] error[E0308]: mismatched types
[INFO] [stderr]   --> src/main.rs:73:21
[INFO] [stderr]    |
[INFO] [stderr] 73 |               None => {
[INFO] [stderr]    |  _____________________^
[INFO] [stderr] 74 | |                 self.curr = &self.head;
[INFO] [stderr] 75 | |             }
[INFO] [stderr]    | |_____________^ expected enum `std::option::Option`, found `()`
[INFO] [stderr]    |
[INFO] [stderr]    = note:   expected enum `std::option::Option<T>`
[INFO] [stderr]            found unit type `()`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 3 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0308`.
[INFO] [stderr] error: could not compile `rust-test`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "293bcfc549a1310c1d13923ab2eba259afbf38d933032f4fefe5c06d140d7176"`
[INFO] running `"docker" "rm" "-f" "293bcfc549a1310c1d13923ab2eba259afbf38d933032f4fefe5c06d140d7176"`
[INFO] [stdout] 293bcfc549a1310c1d13923ab2eba259afbf38d933032f4fefe5c06d140d7176