[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-60039/sources/master#efe2f32a6b8217425f361ec7c206910c611c03ee/gh/isaacazuelos/rs_gc_dead_end"`
[INFO] [stderr] Cloning into 'work/ex/pr-60039/sources/master#efe2f32a6b8217425f361ec7c206910c611c03ee/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-60039/sources/try#78b0bd8441ef961f6475e3d47fe3bca38cb83432/gh/isaacazuelos/rs_gc_dead_end"`
[INFO] [stderr] Cloning into 'work/ex/pr-60039/sources/try#78b0bd8441ef961f6475e3d47fe3bca38cb83432/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#efe2f32a6b8217425f361ec7c206910c611c03ee
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+efe2f32a6b8217425f361ec7c206910c611c03ee-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of isaacazuelos/rs_gc_dead_end on toolchain try#78b0bd8441ef961f6475e3d47fe3bca38cb83432
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+78b0bd8441ef961f6475e3d47fe3bca38cb83432-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-60039/sources/master#efe2f32a6b8217425f361ec7c206910c611c03ee/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-60039/sources/try#78b0bd8441ef961f6475e3d47fe3bca38cb83432/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" "+efe2f32a6b8217425f361ec7c206910c611c03ee-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+78b0bd8441ef961f6475e3d47fe3bca38cb83432-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking isaacazuelos/rs_gc_dead_end against master#efe2f32a6b8217425f361ec7c206910c611c03ee for pr-60039
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-60039/worker-5/master#efe2f32a6b8217425f361ec7c206910c611c03ee:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-60039/sources/master#efe2f32a6b8217425f361ec7c206910c611c03ee/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" "+efe2f32a6b8217425f361ec7c206910c611c03ee-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 634846e2e25d0e3d13a961050c28a9c9f4910cd3b785ef9a7a8257b7dd2ab929
[INFO] running `"docker" "start" "-a" "634846e2e25d0e3d13a961050c28a9c9f4910cd3b785ef9a7a8257b7dd2ab929"`
[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: 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: 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]     Finished dev [unoptimized + debuginfo] target(s) in 0.36s
[INFO] running `"docker" "inspect" "634846e2e25d0e3d13a961050c28a9c9f4910cd3b785ef9a7a8257b7dd2ab929"`
[INFO] running `"docker" "rm" "-f" "634846e2e25d0e3d13a961050c28a9c9f4910cd3b785ef9a7a8257b7dd2ab929"`
[INFO] [stdout] 634846e2e25d0e3d13a961050c28a9c9f4910cd3b785ef9a7a8257b7dd2ab929