[INFO] fetching crate mut_guard 0.1.0...
[INFO] checking mut_guard-0.1.0 against master#936f2600b6c903b04387f74ed5cbce88bb06d243 for pr-91141
[INFO] extracting crate mut_guard 0.1.0 into /workspace/builds/worker-79/source
[INFO] validating manifest of crates.io crate mut_guard 0.1.0 on toolchain 936f2600b6c903b04387f74ed5cbce88bb06d243
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mut_guard 0.1.0
[INFO] finished tweaking crates.io crate mut_guard 0.1.0
[INFO] tweaked toml for crates.io crate mut_guard 0.1.0 written to /workspace/builds/worker-79/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d0eb2c4650d86d1c431529163a546dc7b2c7f3f74be7a1828031d769db8354a4
[INFO] running `Command { std: "docker" "start" "-a" "d0eb2c4650d86d1c431529163a546dc7b2c7f3f74be7a1828031d769db8354a4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d0eb2c4650d86d1c431529163a546dc7b2c7f3f74be7a1828031d769db8354a4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d0eb2c4650d86d1c431529163a546dc7b2c7f3f74be7a1828031d769db8354a4", kill_on_drop: false }`
[INFO] [stdout] d0eb2c4650d86d1c431529163a546dc7b2c7f3f74be7a1828031d769db8354a4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ed4366b4d6c71308627cc326280084ffa54f6fec4db65248295b99f5d424ac5f
[INFO] running `Command { std: "docker" "start" "-a" "ed4366b4d6c71308627cc326280084ffa54f6fec4db65248295b99f5d424ac5f", kill_on_drop: false }`
[INFO] [stderr]     Checking itoa v0.4.8
[INFO] [stderr]     Checking mut_guard v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]    Compiling syn v1.0.82
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:211:12
[INFO] [stdout]     |
[INFO] [stdout] 211 |     f: Box<'a + FnMut(&mut T)>,
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn 'a + FnMut(&mut T)`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking serde_json v1.0.72
[INFO] [stderr]    Compiling serde_derive v1.0.130
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:211:12
[INFO] [stdout]     |
[INFO] [stdout] 211 |     f: Box<'a + FnMut(&mut T)>,
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn 'a + FnMut(&mut T)`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 10.54s
[INFO] running `Command { std: "docker" "inspect" "ed4366b4d6c71308627cc326280084ffa54f6fec4db65248295b99f5d424ac5f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ed4366b4d6c71308627cc326280084ffa54f6fec4db65248295b99f5d424ac5f", kill_on_drop: false }`
[INFO] [stdout] ed4366b4d6c71308627cc326280084ffa54f6fec4db65248295b99f5d424ac5f