[INFO] updating cached repository isaacazuelos/rs_gc_dead_end
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/isaacazuelos/rs_gc_dead_end
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/isaacazuelos/rs_gc_dead_end" "work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/isaacazuelos/rs_gc_dead_end"`
[INFO] [stderr] Cloning into 'work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/isaacazuelos/rs_gc_dead_end'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/isaacazuelos/rs_gc_dead_end" "work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/isaacazuelos/rs_gc_dead_end"`
[INFO] [stderr] Cloning into 'work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/isaacazuelos/rs_gc_dead_end'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 38eb6324bcc278465b11a905cc72a55e380626c3
[INFO] sha for GitHub repo isaacazuelos/rs_gc_dead_end: 38eb6324bcc278465b11a905cc72a55e380626c3
[INFO] validating manifest of isaacazuelos/rs_gc_dead_end on toolchain master#60960a260f7b5c695fd0717311d72ce62dd4eb43
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+60960a260f7b5c695fd0717311d72ce62dd4eb43-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of isaacazuelos/rs_gc_dead_end on toolchain try#266783e4e09e4e9d5307c1c8e695659c58bbcac7
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+266783e4e09e4e9d5307c1c8e695659c58bbcac7-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing isaacazuelos/rs_gc_dead_end
[INFO] finished frobbing isaacazuelos/rs_gc_dead_end
[INFO] frobbed toml for isaacazuelos/rs_gc_dead_end written to work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/isaacazuelos/rs_gc_dead_end/Cargo.toml
[INFO] started frobbing isaacazuelos/rs_gc_dead_end
[INFO] finished frobbing isaacazuelos/rs_gc_dead_end
[INFO] frobbed toml for isaacazuelos/rs_gc_dead_end written to work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/isaacazuelos/rs_gc_dead_end/Cargo.toml
[INFO] crate isaacazuelos/rs_gc_dead_end already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+60960a260f7b5c695fd0717311d72ce62dd4eb43-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+266783e4e09e4e9d5307c1c8e695659c58bbcac7-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking isaacazuelos/rs_gc_dead_end against try#266783e4e09e4e9d5307c1c8e695659c58bbcac7 for pr-63376
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-63376/worker-3/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/isaacazuelos/rs_gc_dead_end:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+266783e4e09e4e9d5307c1c8e695659c58bbcac7-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 794621085d1af266fce6a386175eb68a51820512b9b23b957e9b4890a35fbf93
[INFO] running `"docker" "start" "-a" "794621085d1af266fce6a386175eb68a51820512b9b23b957e9b4890a35fbf93"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking gc v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stderr]    --> src/main.rs:164:9
[INFO] [stderr]     |
[INFO] [stderr] 164 |     let a = heap.intern(Node::new("a"));
[INFO] [stderr]     |         ^ help: consider prefixing with an underscore: `_a`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]    --> src/main.rs:165:9
[INFO] [stderr]     |
[INFO] [stderr] 165 |     let b = heap.intern(Node::new("b"));
[INFO] [stderr]     |         ^ help: consider prefixing with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `root`
[INFO] [stderr]   --> src/main.rs:85:24
[INFO] [stderr]    |
[INFO] [stderr] 85 |     fn mark(&mut self, root: &mut Gc<T>) {
[INFO] [stderr]    |                        ^^^^ help: consider prefixing with an underscore: `_root`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stderr]    --> src/main.rs:164:9
[INFO] [stderr]     |
[INFO] [stderr] 164 |     let a = heap.intern(Node::new("a"));
[INFO] [stderr]     |         ^ help: consider prefixing with an underscore: `_a`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]    --> src/main.rs:165:9
[INFO] [stderr]     |
[INFO] [stderr] 165 |     let b = heap.intern(Node::new("b"));
[INFO] [stderr]     |         ^ help: consider prefixing with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `root`
[INFO] [stderr]   --> src/main.rs:85:24
[INFO] [stderr]    |
[INFO] [stderr] 85 |     fn mark(&mut self, root: &mut Gc<T>) {
[INFO] [stderr]    |                        ^^^^ help: consider prefixing with an underscore: `_root`
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `collect`
[INFO] [stderr]   --> src/main.rs:80:5
[INFO] [stderr]    |
[INFO] [stderr] 80 |     fn collect(&mut self, root: &mut Gc<T>) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `mark`
[INFO] [stderr]   --> src/main.rs:85:5
[INFO] [stderr]    |
[INFO] [stderr] 85 |     fn mark(&mut self, root: &mut Gc<T>) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `sweep`
[INFO] [stderr]   --> src/main.rs:89:5
[INFO] [stderr]    |
[INFO] [stderr] 89 |     unsafe fn sweep(&mut self) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push_edge`
[INFO] [stderr]    --> src/main.rs:152:5
[INFO] [stderr]     |
[INFO] [stderr] 152 |     fn push_edge(&'a mut self, edge: Gc<'a, Node<'a>>) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `collect`
[INFO] [stderr]   --> src/main.rs:80:5
[INFO] [stderr]    |
[INFO] [stderr] 80 |     fn collect(&mut self, root: &mut Gc<T>) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `mark`
[INFO] [stderr]   --> src/main.rs:85:5
[INFO] [stderr]    |
[INFO] [stderr] 85 |     fn mark(&mut self, root: &mut Gc<T>) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `sweep`
[INFO] [stderr]   --> src/main.rs:89:5
[INFO] [stderr]    |
[INFO] [stderr] 89 |     unsafe fn sweep(&mut self) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push_edge`
[INFO] [stderr]    --> src/main.rs:152:5
[INFO] [stderr]     |
[INFO] [stderr] 152 |     fn push_edge(&'a mut self, edge: Gc<'a, Node<'a>>) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.57s
[INFO] running `"docker" "inspect" "794621085d1af266fce6a386175eb68a51820512b9b23b957e9b4890a35fbf93"`
[INFO] running `"docker" "rm" "-f" "794621085d1af266fce6a386175eb68a51820512b9b23b957e9b4890a35fbf93"`
[INFO] [stdout] 794621085d1af266fce6a386175eb68a51820512b9b23b957e9b4890a35fbf93