[INFO] updating cached repository https://github.com/nerdrew/rust-self-referential-struct
[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] e8cf708ceb78d9f3ad950cb6f609a7c7a5336b71
[INFO] checking nerdrew/rust-self-referential-struct against try#f88e9a4452e792c29632101b348a1df9876d45cd for pr-70087
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnerdrew%2Frust-self-referential-struct" "/workspace/builds/worker-9/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/nerdrew/rust-self-referential-struct on toolchain f88e9a4452e792c29632101b348a1df9876d45cd
[INFO] running `"/workspace/cargo-home/bin/cargo" "+f88e9a4452e792c29632101b348a1df9876d45cd" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/nerdrew/rust-self-referential-struct
[INFO] finished tweaking git repo https://github.com/nerdrew/rust-self-referential-struct
[INFO] tweaked toml for git repo https://github.com/nerdrew/rust-self-referential-struct written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/nerdrew/rust-self-referential-struct already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+f88e9a4452e792c29632101b348a1df9876d45cd" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "/opt/rustwide/cargo-home/bin/cargo" "+f88e9a4452e792c29632101b348a1df9876d45cd" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 56600124d281700f035ffa339b2837d463fc06db3ffb853c63fe96ca89186548
[INFO] running `"docker" "start" "-a" "56600124d281700f035ffa339b2837d463fc06db3ffb853c63fe96ca89186548"`
[INFO] [stderr]     Checking rust-self-referential-struct v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:67:9
[INFO] [stderr]    |
[INFO] [stderr] 67 |     let mut owned = Owned::from("I see you".to_string());
[INFO] [stderr]    |         ----^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:67:9
[INFO] [stderr]    |
[INFO] [stderr] 67 |     let mut owned = Owned::from("I see you".to_string());
[INFO] [stderr]    |         ----^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.00s
[INFO] running `"docker" "inspect" "56600124d281700f035ffa339b2837d463fc06db3ffb853c63fe96ca89186548"`
[INFO] running `"docker" "rm" "-f" "56600124d281700f035ffa339b2837d463fc06db3ffb853c63fe96ca89186548"`
[INFO] [stdout] 56600124d281700f035ffa339b2837d463fc06db3ffb853c63fe96ca89186548