[INFO] cloning repository https://github.com/xiaowang7777/graph_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/xiaowang7777/graph_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxiaowang7777%2Fgraph_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxiaowang7777%2Fgraph_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] dfca29a94b6348ee307d639ae989305c7030f21d
[INFO] checking xiaowang7777/graph_rust against try#a3dffdb3a32d0dedc198f9de7d43173f3eb6727b for pr-136303
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxiaowang7777%2Fgraph_rust" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/xiaowang7777/graph_rust on toolchain a3dffdb3a32d0dedc198f9de7d43173f3eb6727b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a3dffdb3a32d0dedc198f9de7d43173f3eb6727b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/xiaowang7777/graph_rust
[INFO] finished tweaking git repo https://github.com/xiaowang7777/graph_rust
[INFO] tweaked toml for git repo https://github.com/xiaowang7777/graph_rust written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/xiaowang7777/graph_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a3dffdb3a32d0dedc198f9de7d43173f3eb6727b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] checking xiaowang7777/graph_rust against try#a3dffdb3a32d0dedc198f9de7d43173f3eb6727b for pr-136303
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxiaowang7777%2Fgraph_rust" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/xiaowang7777/graph_rust on toolchain a3dffdb3a32d0dedc198f9de7d43173f3eb6727b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a3dffdb3a32d0dedc198f9de7d43173f3eb6727b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/xiaowang7777/graph_rust
[INFO] finished tweaking git repo https://github.com/xiaowang7777/graph_rust
[INFO] tweaked toml for git repo https://github.com/xiaowang7777/graph_rust written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/xiaowang7777/graph_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a3dffdb3a32d0dedc198f9de7d43173f3eb6727b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:c80049f3b88b82089a44e0f06d0d6029d44b96b7257e55a1cd63dbc9f4c33334" "/opt/rustwide/cargo-home/bin/cargo" "+a3dffdb3a32d0dedc198f9de7d43173f3eb6727b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] Error response from daemon: mkdir /var/lib/docker/overlay2/310b879b318ba271a2567a965466255c25a9771c0fc8fa97e4ef8663462c3246/diff: no space left on device
[INFO] checking xiaowang7777/graph_rust against try#a3dffdb3a32d0dedc198f9de7d43173f3eb6727b for pr-136303
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxiaowang7777%2Fgraph_rust" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'...
[INFO] [stderr] done.
[INFO] [stderr] error: unable to write file src/graph.rs
[INFO] [stderr] fatal: cannot create directory at 'src/graph': No space left on device
[INFO] [stderr] warning: Clone succeeded, but checkout failed.
[INFO] [stderr] You can inspect what was checked out with 'git status'
[INFO] [stderr] and retry with 'git restore --source=HEAD :/'
[INFO] [stderr] 
[INFO] checking xiaowang7777/graph_rust against try#a3dffdb3a32d0dedc198f9de7d43173f3eb6727b for pr-136303
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxiaowang7777%2Fgraph_rust" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'...
[INFO] [stderr] done.
[INFO] [stderr] fatal: sha1 file '/workspace/builds/worker-5-tc2/source/.git/index.lock' write error. Out of diskspace
[INFO] [stderr] warning: Clone succeeded, but checkout failed.
[INFO] [stderr] You can inspect what was checked out with 'git status'
[INFO] [stderr] and retry with 'git restore --source=HEAD :/'
[INFO] [stderr] 
[INFO] checking xiaowang7777/graph_rust against try#a3dffdb3a32d0dedc198f9de7d43173f3eb6727b for pr-136303
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxiaowang7777%2Fgraph_rust" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/xiaowang7777/graph_rust on toolchain a3dffdb3a32d0dedc198f9de7d43173f3eb6727b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a3dffdb3a32d0dedc198f9de7d43173f3eb6727b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/xiaowang7777/graph_rust
[INFO] finished tweaking git repo https://github.com/xiaowang7777/graph_rust
[INFO] tweaked toml for git repo https://github.com/xiaowang7777/graph_rust written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/xiaowang7777/graph_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a3dffdb3a32d0dedc198f9de7d43173f3eb6727b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:c80049f3b88b82089a44e0f06d0d6029d44b96b7257e55a1cd63dbc9f4c33334" "/opt/rustwide/cargo-home/bin/cargo" "+a3dffdb3a32d0dedc198f9de7d43173f3eb6727b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 20dffeccb0735ee644324fcc5112138e3e2666247ff064c84d0b46153a9294fe
[INFO] running `Command { std: "docker" "start" "-a" "20dffeccb0735ee644324fcc5112138e3e2666247ff064c84d0b46153a9294fe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "20dffeccb0735ee644324fcc5112138e3e2666247ff064c84d0b46153a9294fe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "20dffeccb0735ee644324fcc5112138e3e2666247ff064c84d0b46153a9294fe", kill_on_drop: false }`
[INFO] [stdout] 20dffeccb0735ee644324fcc5112138e3e2666247ff064c84d0b46153a9294fe
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:c80049f3b88b82089a44e0f06d0d6029d44b96b7257e55a1cd63dbc9f4c33334" "/opt/rustwide/cargo-home/bin/cargo" "+a3dffdb3a32d0dedc198f9de7d43173f3eb6727b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bea07d38f62fc40813ed032d08c1a8982729c87f301fae877759cdd99b0b8831
[INFO] running `Command { std: "docker" "start" "-a" "bea07d38f62fc40813ed032d08c1a8982729c87f301fae877759cdd99b0b8831", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_stu v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::any::TypeId`
[INFO] [stdout]  --> src/graph.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::any::TypeId;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::Read`
[INFO] [stdout]  --> src/graph.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::io::Read;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `GraphPath` and `Graph`
[INFO] [stdout]    --> src/graph/simple.rs:203:24
[INFO] [stdout]     |
[INFO] [stdout] 203 |     use crate::graph::{Graph, GraphPath};
[INFO] [stdout]     |                        ^^^^^  ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::graph::simple::SimpleGraph`
[INFO] [stdout]    --> src/graph/simple.rs:204:9
[INFO] [stdout]     |
[INFO] [stdout] 204 |     use crate::graph::simple::SimpleGraph;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `GraphPath` and `Graph`
[INFO] [stdout]    --> src/graph/safe_simple.rs:185:24
[INFO] [stdout]     |
[INFO] [stdout] 185 |     use crate::graph::{Graph, GraphPath};
[INFO] [stdout]     |                        ^^^^^  ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::graph::simple::SimpleGraph`
[INFO] [stdout]    --> src/graph/safe_simple.rs:186:9
[INFO] [stdout]     |
[INFO] [stdout] 186 |     use crate::graph::simple::SimpleGraph;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::any::TypeId`
[INFO] [stdout]  --> src/graph.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::any::TypeId;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::Read`
[INFO] [stdout]  --> src/graph.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::io::Read;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/graph.rs:33:19
[INFO] [stdout]    |
[INFO] [stdout] 33 |     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
[INFO] [stdout]    |                   ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/graph.rs:39:19
[INFO] [stdout]    |
[INFO] [stdout] 39 |     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
[INFO] [stdout]    |                   ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/graph.rs:33:19
[INFO] [stdout]    |
[INFO] [stdout] 33 |     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
[INFO] [stdout]    |                   ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/graph.rs:39:19
[INFO] [stdout]    |
[INFO] [stdout] 39 |     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
[INFO] [stdout]    |                   ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `reader`
[INFO] [stdout]   --> src/graph/simple.rs:34:24
[INFO] [stdout]    |
[INFO] [stdout] 34 |     fn new_with_reader(reader: Box<dyn Read>) -> Self {
[INFO] [stdout]    |                        ^^^^^^ help: if this is intentional, prefix it with an underscore: `_reader`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `reader`
[INFO] [stdout]   --> src/graph/simple.rs:34:24
[INFO] [stdout]    |
[INFO] [stdout] 34 |     fn new_with_reader(reader: Box<dyn Read>) -> Self {
[INFO] [stdout]    |                        ^^^^^^ help: if this is intentional, prefix it with an underscore: `_reader`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/graph/simple.rs:82:21
[INFO] [stdout]    |
[INFO] [stdout] 82 |     fn to_bfs(self, v: usize) -> Self::BFSItem {
[INFO] [stdout]    |                     ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/graph/simple.rs:82:21
[INFO] [stdout]    |
[INFO] [stdout] 82 |     fn to_bfs(self, v: usize) -> Self::BFSItem {
[INFO] [stdout]    |                     ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/graph/simple.rs:104:13
[INFO] [stdout]     |
[INFO] [stdout] 104 |         let mut p = SimpleDFSGraphPath {
[INFO] [stdout]     |             ----^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/graph/simple.rs:104:13
[INFO] [stdout]     |
[INFO] [stdout] 104 |         let mut p = SimpleDFSGraphPath {
[INFO] [stdout]     |             ----^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `reader`
[INFO] [stdout]   --> src/graph/safe_simple.rs:34:24
[INFO] [stdout]    |
[INFO] [stdout] 34 |     fn new_with_reader(reader: Box<dyn Read>) -> Self {
[INFO] [stdout]    |                        ^^^^^^ help: if this is intentional, prefix it with an underscore: `_reader`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `reader`
[INFO] [stdout]   --> src/graph/safe_simple.rs:34:24
[INFO] [stdout]    |
[INFO] [stdout] 34 |     fn new_with_reader(reader: Box<dyn Read>) -> Self {
[INFO] [stdout]    |                        ^^^^^^ help: if this is intentional, prefix it with an underscore: `_reader`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/graph/safe_simple.rs:82:21
[INFO] [stdout]    |
[INFO] [stdout] 82 |     fn to_bfs(self, v: usize) -> Self::BFSItem {
[INFO] [stdout]    |                     ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/graph/safe_simple.rs:82:21
[INFO] [stdout]    |
[INFO] [stdout] 82 |     fn to_bfs(self, v: usize) -> Self::BFSItem {
[INFO] [stdout]    |                     ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0499]: cannot borrow `*self` as mutable more than once at a time
[INFO] [stdout]    --> src/graph/safe_simple.rs:136:17
[INFO] [stdout]     |
[INFO] [stdout] 123 |         if let Some(node) = (&mut self.list).get_mut(point) {
[INFO] [stdout]     |                             ---------------- first mutable borrow occurs here
[INFO] [stdout] 124 |             let mut len: usize = 0;
[INFO] [stdout] 125 |             while let Some(&mut n) = (&mut node.list).get_mut(len) {
[INFO] [stdout]     |                                      ---------------- first borrow later used here
[INFO] [stdout] ...
[INFO] [stdout] 136 |                 self.dfs(n as usize);
[INFO] [stdout]     |                 ^^^^ second mutable borrow occurs here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0499]: cannot borrow `*self` as mutable more than once at a time
[INFO] [stdout]    --> src/graph/safe_simple.rs:136:17
[INFO] [stdout]     |
[INFO] [stdout] 123 |         if let Some(node) = (&mut self.list).get_mut(point) {
[INFO] [stdout]     |                             ---------------- first mutable borrow occurs here
[INFO] [stdout] 124 |             let mut len: usize = 0;
[INFO] [stdout] 125 |             while let Some(&mut n) = (&mut node.list).get_mut(len) {
[INFO] [stdout]     |                                      ---------------- first borrow later used here
[INFO] [stdout] ...
[INFO] [stdout] 136 |                 self.dfs(n as usize);
[INFO] [stdout]     |                 ^^^^ second mutable borrow occurs here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0499`.
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0499`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_stu` (bin "rust_stu") due to 1 previous error; 13 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `rust_stu` (bin "rust_stu" test) due to 1 previous error; 9 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "bea07d38f62fc40813ed032d08c1a8982729c87f301fae877759cdd99b0b8831", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bea07d38f62fc40813ed032d08c1a8982729c87f301fae877759cdd99b0b8831", kill_on_drop: false }`
[INFO] [stdout] bea07d38f62fc40813ed032d08c1a8982729c87f301fae877759cdd99b0b8831
