[INFO] cloning repository https://github.com/CrimsonAndRed/MyLittleTree
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/CrimsonAndRed/MyLittleTree" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCrimsonAndRed%2FMyLittleTree", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCrimsonAndRed%2FMyLittleTree'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 78579106ceda8e62514cfb157392a5c603b54fdf
[INFO] checking CrimsonAndRed/MyLittleTree against beta-2020-07-24 for pr-75494-beta
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCrimsonAndRed%2FMyLittleTree" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/CrimsonAndRed/MyLittleTree 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/CrimsonAndRed/MyLittleTree
[INFO] finished tweaking git repo https://github.com/CrimsonAndRed/MyLittleTree
[INFO] tweaked toml for git repo https://github.com/CrimsonAndRed/MyLittleTree written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/CrimsonAndRed/MyLittleTree 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4467bb12b9def2c154260170e409a09ed9be6e1262405aff0795ac1a47160297
[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" "4467bb12b9def2c154260170e409a09ed9be6e1262405aff0795ac1a47160297", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4467bb12b9def2c154260170e409a09ed9be6e1262405aff0795ac1a47160297", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4467bb12b9def2c154260170e409a09ed9be6e1262405aff0795ac1a47160297", kill_on_drop: false }`
[INFO] [stdout] 4467bb12b9def2c154260170e409a09ed9be6e1262405aff0795ac1a47160297
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fed37f51a6ce26903d19db8a26cdbfd8d42d883493ce0526c9a1e4f0d0c43ac1
[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" "fed37f51a6ce26903d19db8a26cdbfd8d42d883493ce0526c9a1e4f0d0c43ac1", kill_on_drop: false }`
[INFO] [stderr]     Checking my_little_tree v1.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: cannot borrow `*self` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/lib.rs:108:27
[INFO] [stdout]     |
[INFO] [stdout] 102 |         match &self.root {
[INFO] [stdout]     |               ---------- immutable borrow occurs here
[INFO] [stdout] ...
[INFO] [stdout] 108 |             Some(link) => self.inner_insert(new_node, Rc::clone(&link)),
[INFO] [stdout]     |                           ^^^^ mutable borrow occurs here       ----- immutable borrow later used here
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
[INFO] [stdout]     = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stdout]     = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: cannot borrow `*self` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/lib.rs:108:27
[INFO] [stdout]     |
[INFO] [stdout] 102 |         match &self.root {
[INFO] [stdout]     |               ---------- immutable borrow occurs here
[INFO] [stdout] ...
[INFO] [stdout] 108 |             Some(link) => self.inner_insert(new_node, Rc::clone(&link)),
[INFO] [stdout]     |                           ^^^^ mutable borrow occurs here       ----- immutable borrow later used here
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
[INFO] [stdout]     = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stdout]     = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.38s
[INFO] running `Command { std: "docker" "inspect" "fed37f51a6ce26903d19db8a26cdbfd8d42d883493ce0526c9a1e4f0d0c43ac1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fed37f51a6ce26903d19db8a26cdbfd8d42d883493ce0526c9a1e4f0d0c43ac1", kill_on_drop: false }`
[INFO] [stdout] fed37f51a6ce26903d19db8a26cdbfd8d42d883493ce0526c9a1e4f0d0c43ac1
