[INFO] fetching crate managed-heap 0.1.5...
[INFO] checking managed-heap-0.1.5 against try#a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d for pr-145342-1
[INFO] extracting crate managed-heap 0.1.5 into /workspace/builds/worker-6-tc2/source
[INFO] started tweaking crates.io crate managed-heap 0.1.5
[INFO] finished tweaking crates.io crate managed-heap 0.1.5
[INFO] tweaked toml for crates.io crate managed-heap 0.1.5 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate managed-heap 0.1.5 on toolchain a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 50ebb2af0bf3f89ddf0c5760ed339725d7f91c17673b1fba31ae6344491b18b6
[INFO] running `Command { std: "docker" "start" "-a" "50ebb2af0bf3f89ddf0c5760ed339725d7f91c17673b1fba31ae6344491b18b6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "50ebb2af0bf3f89ddf0c5760ed339725d7f91c17673b1fba31ae6344491b18b6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "50ebb2af0bf3f89ddf0c5760ed339725d7f91c17673b1fba31ae6344491b18b6", kill_on_drop: false }`
[INFO] [stdout] 50ebb2af0bf3f89ddf0c5760ed339725d7f91c17673b1fba31ae6344491b18b6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 180fdeb3ecedf447f5b88723c2af8f019cf90fa1059ec84fcd5faf67d5700df0
[INFO] running `Command { std: "docker" "start" "-a" "180fdeb3ecedf447f5b88723c2af8f019cf90fa1059ec84fcd5faf67d5700df0", kill_on_drop: false }`
[INFO] [stderr]     Checking managed-heap v0.1.5 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:101:50
[INFO] [stdout]     |
[INFO] [stdout] 101 |             fn children<'a>(&'a mut self) -> Box<Iterator<Item = &'a mut IntegerObject> + 'a> {
[INFO] [stdout]     |                                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]     = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 101 |             fn children<'a>(&'a mut self) -> Box<dyn Iterator<Item = &'a mut IntegerObject> + 'a> {
[INFO] [stdout]     |                                                  +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/trace.rs:20:42
[INFO] [stdout]    |
[INFO] [stdout] 20 |     fn children<'a>(&'a mut self) -> Box<Iterator<Item = &'a mut I> + 'a>;
[INFO] [stdout]    |                                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 20 |     fn children<'a>(&'a mut self) -> Box<dyn Iterator<Item = &'a mut I> + 'a>;
[INFO] [stdout]    |                                          +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:215:50
[INFO] [stdout]     |
[INFO] [stdout] 215 |             fn children<'a>(&'a mut self) -> Box<Iterator<Item = &'a mut LinkedList> + 'a> {
[INFO] [stdout]     |                                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 215 |             fn children<'a>(&'a mut self) -> Box<dyn Iterator<Item = &'a mut LinkedList> + 'a> {
[INFO] [stdout]     |                                                  +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/block/set.rs:23:38
[INFO] [stdout]    |
[INFO] [stdout] 23 |     pub fn iter<'a>(&'a self) -> Box<Iterator<Item = &Block> + 'a> {
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 23 |     pub fn iter<'a>(&'a self) -> Box<dyn Iterator<Item = &Block> + 'a> {
[INFO] [stdout]    |                                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/heap.rs:144:38
[INFO] [stdout]     |
[INFO] [stdout] 144 |     pub fn used<'a>(&'a self) -> Box<Iterator<Item = &Block> + 'a> {
[INFO] [stdout]     |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 144 |     pub fn used<'a>(&'a self) -> Box<dyn Iterator<Item = &Block> + 'a> {
[INFO] [stdout]     |                                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/managed.rs:50:47
[INFO] [stdout]    |
[INFO] [stdout] 50 |     pub fn gc<T>(&mut self, roots: &mut [&mut GcRoot<T>])
[INFO] [stdout]    |                                               ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 50 |     pub fn gc<T>(&mut self, roots: &mut [&mut dyn GcRoot<T>])
[INFO] [stdout]    |                                               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:173:41
[INFO] [stdout]     |
[INFO] [stdout] 173 |                 let mut roots: Vec<&mut GcRoot<IntegerObject>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 173 |                 let mut roots: Vec<&mut dyn GcRoot<IntegerObject>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:180:41
[INFO] [stdout]     |
[INFO] [stdout] 180 |                 let mut roots: Vec<&mut GcRoot<IntegerObject>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 180 |                 let mut roots: Vec<&mut dyn GcRoot<IntegerObject>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:187:37
[INFO] [stdout]     |
[INFO] [stdout] 187 |             let mut roots: Vec<&mut GcRoot<IntegerObject>> = vec![&mut gc_root];
[INFO] [stdout]     |                                     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 187 |             let mut roots: Vec<&mut dyn GcRoot<IntegerObject>> = vec![&mut gc_root];
[INFO] [stdout]     |                                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:364:41
[INFO] [stdout]     |
[INFO] [stdout] 364 |                 let mut roots: Vec<&mut GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 364 |                 let mut roots: Vec<&mut dyn GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:371:41
[INFO] [stdout]     |
[INFO] [stdout] 371 |                 let mut roots: Vec<&mut GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 371 |                 let mut roots: Vec<&mut dyn GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:378:37
[INFO] [stdout]     |
[INFO] [stdout] 378 |             let mut roots: Vec<&mut GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 378 |             let mut roots: Vec<&mut dyn GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:395:41
[INFO] [stdout]     |
[INFO] [stdout] 395 |                 let mut roots: Vec<&mut GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 395 |                 let mut roots: Vec<&mut dyn GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:403:41
[INFO] [stdout]     |
[INFO] [stdout] 403 |                 let mut roots: Vec<&mut GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 403 |                 let mut roots: Vec<&mut dyn GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:411:37
[INFO] [stdout]     |
[INFO] [stdout] 411 |             let mut roots: Vec<&mut GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 411 |             let mut roots: Vec<&mut dyn GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:431:45
[INFO] [stdout]     |
[INFO] [stdout] 431 |                     let mut roots: Vec<&mut GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                             ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 431 |                     let mut roots: Vec<&mut dyn GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                             +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:438:45
[INFO] [stdout]     |
[INFO] [stdout] 438 |                     let mut roots: Vec<&mut GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                             ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 438 |                     let mut roots: Vec<&mut dyn GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                             +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:445:41
[INFO] [stdout]     |
[INFO] [stdout] 445 |                 let mut roots: Vec<&mut GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 445 |                 let mut roots: Vec<&mut dyn GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/managed.rs:450:41
[INFO] [stdout]     |
[INFO] [stdout] 450 |                 let mut roots: Vec<&mut GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 450 |                 let mut roots: Vec<&mut dyn GcRoot<LinkedList>> = vec![&mut gc_root];
[INFO] [stdout]     |                                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: eliding a lifetime that's named elsewhere is confusing
[INFO] [stdout]   --> src/block/set.rs:23:22
[INFO] [stdout]    |
[INFO] [stdout] 23 |     pub fn iter<'a>(&'a self) -> Box<Iterator<Item = &Block> + 'a> {
[INFO] [stdout]    |                      ^^ the lifetime is named here   ------ the same lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: consistently use `'a`
[INFO] [stdout]    |
[INFO] [stdout] 23 |     pub fn iter<'a>(&'a self) -> Box<Iterator<Item = &'a Block> + 'a> {
[INFO] [stdout]    |                                                       ++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: eliding a lifetime that's named elsewhere is confusing
[INFO] [stdout]    --> src/heap.rs:144:22
[INFO] [stdout]     |
[INFO] [stdout] 144 |     pub fn used<'a>(&'a self) -> Box<Iterator<Item = &Block> + 'a> {
[INFO] [stdout]     |                      ^^ the lifetime is named here   ------ the same lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: consistently use `'a`
[INFO] [stdout]     |
[INFO] [stdout] 144 |     pub fn used<'a>(&'a self) -> Box<Iterator<Item = &'a Block> + 'a> {
[INFO] [stdout]     |                                                       ++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/block/set.rs:23:38
[INFO] [stdout]    |
[INFO] [stdout] 23 |     pub fn iter<'a>(&'a self) -> Box<Iterator<Item = &Block> + 'a> {
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 23 |     pub fn iter<'a>(&'a self) -> Box<dyn Iterator<Item = &Block> + 'a> {
[INFO] [stdout]    |                                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/heap.rs:144:38
[INFO] [stdout]     |
[INFO] [stdout] 144 |     pub fn used<'a>(&'a self) -> Box<Iterator<Item = &Block> + 'a> {
[INFO] [stdout]     |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 144 |     pub fn used<'a>(&'a self) -> Box<dyn Iterator<Item = &Block> + 'a> {
[INFO] [stdout]     |                                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/managed.rs:50:47
[INFO] [stdout]    |
[INFO] [stdout] 50 |     pub fn gc<T>(&mut self, roots: &mut [&mut GcRoot<T>])
[INFO] [stdout]    |                                               ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 50 |     pub fn gc<T>(&mut self, roots: &mut [&mut dyn GcRoot<T>])
[INFO] [stdout]    |                                               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/trace.rs:20:42
[INFO] [stdout]    |
[INFO] [stdout] 20 |     fn children<'a>(&'a mut self) -> Box<Iterator<Item = &'a mut I> + 'a>;
[INFO] [stdout]    |                                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 20 |     fn children<'a>(&'a mut self) -> Box<dyn Iterator<Item = &'a mut I> + 'a>;
[INFO] [stdout]    |                                          +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: eliding a lifetime that's named elsewhere is confusing
[INFO] [stdout]   --> src/block/set.rs:23:22
[INFO] [stdout]    |
[INFO] [stdout] 23 |     pub fn iter<'a>(&'a self) -> Box<Iterator<Item = &Block> + 'a> {
[INFO] [stdout]    |                      ^^ the lifetime is named here   ------ the same lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: consistently use `'a`
[INFO] [stdout]    |
[INFO] [stdout] 23 |     pub fn iter<'a>(&'a self) -> Box<Iterator<Item = &'a Block> + 'a> {
[INFO] [stdout]    |                                                       ++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: eliding a lifetime that's named elsewhere is confusing
[INFO] [stdout]    --> src/heap.rs:144:22
[INFO] [stdout]     |
[INFO] [stdout] 144 |     pub fn used<'a>(&'a self) -> Box<Iterator<Item = &Block> + 'a> {
[INFO] [stdout]     |                      ^^ the lifetime is named here   ------ the same lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: consistently use `'a`
[INFO] [stdout]     |
[INFO] [stdout] 144 |     pub fn used<'a>(&'a self) -> Box<Iterator<Item = &'a Block> + 'a> {
[INFO] [stdout]     |                                                       ++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.35s
[INFO] running `Command { std: "docker" "inspect" "180fdeb3ecedf447f5b88723c2af8f019cf90fa1059ec84fcd5faf67d5700df0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "180fdeb3ecedf447f5b88723c2af8f019cf90fa1059ec84fcd5faf67d5700df0", kill_on_drop: false }`
[INFO] [stdout] 180fdeb3ecedf447f5b88723c2af8f019cf90fa1059ec84fcd5faf67d5700df0