[INFO] cloning repository https://github.com/cybermatt/fast-luhn
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/cybermatt/fast-luhn" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcybermatt%2Ffast-luhn", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcybermatt%2Ffast-luhn'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 39f9395960c3176672290965160264d009bc378b
[INFO] checking cybermatt/fast-luhn against try#c8085cfed34c45021fc8f66d073f6394b3e35431 for pr-148939
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcybermatt%2Ffast-luhn" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/cybermatt/fast-luhn
[INFO] finished tweaking git repo https://github.com/cybermatt/fast-luhn
[INFO] tweaked toml for git repo https://github.com/cybermatt/fast-luhn written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/cybermatt/fast-luhn on toolchain c8085cfed34c45021fc8f66d073f6394b3e35431
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c8085cfed34c45021fc8f66d073f6394b3e35431" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/cybermatt/fast-luhn 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" "+c8085cfed34c45021fc8f66d073f6394b3e35431" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded paste v0.1.18
[INFO] [stderr]   Downloaded autocfg v0.1.2
[INFO] [stderr]   Downloaded indoc v0.3.6
[INFO] [stderr]   Downloaded ctor v0.1.16
[INFO] [stderr]   Downloaded unindent v0.1.7
[INFO] [stderr]   Downloaded indoc-impl v0.3.6
[INFO] [stderr]   Downloaded rand_jitter v0.1.3
[INFO] [stderr]   Downloaded ghost v0.1.2
[INFO] [stderr]   Downloaded inventory-impl v0.1.10
[INFO] [stderr]   Downloaded inventory v0.1.10
[INFO] [stderr]   Downloaded parking_lot_core v0.8.1
[INFO] [stderr]   Downloaded paste-impl v0.1.18
[INFO] [stderr]   Downloaded syn v1.0.54
[INFO] [stderr]   Downloaded pyo3-derive-backend v0.12.4
[INFO] [stderr]   Downloaded pyo3cls v0.12.4
[INFO] [stderr]   Downloaded rand_core v0.4.0
[INFO] [stderr]   Downloaded pyo3 v0.12.4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+c8085cfed34c45021fc8f66d073f6394b3e35431" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 071ec923f507c7697dc4fa4cb54ae3261d1f86c89955bfb57b36869614878c24
[INFO] running `Command { std: "docker" "start" "-a" "071ec923f507c7697dc4fa4cb54ae3261d1f86c89955bfb57b36869614878c24", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "071ec923f507c7697dc4fa4cb54ae3261d1f86c89955bfb57b36869614878c24", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "071ec923f507c7697dc4fa4cb54ae3261d1f86c89955bfb57b36869614878c24", kill_on_drop: false }`
[INFO] [stdout] 071ec923f507c7697dc4fa4cb54ae3261d1f86c89955bfb57b36869614878c24
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+c8085cfed34c45021fc8f66d073f6394b3e35431" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7a2ae1e27a06eefe5d886554f733e4efdb6fadedb1b073e7f094199a93909c54
[INFO] running `Command { std: "docker" "start" "-a" "7a2ae1e27a06eefe5d886554f733e4efdb6fadedb1b073e7f094199a93909c54", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.54
[INFO] [stderr]    Compiling autocfg v0.1.2
[INFO] [stderr]     Checking rand_core v0.4.0
[INFO] [stderr]    Compiling libc v0.2.81
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling unindent v0.1.7
[INFO] [stderr]     Checking smallvec v1.8.0
[INFO] [stderr]    Compiling inventory v0.1.10
[INFO] [stderr]    Compiling pyo3 v0.12.4
[INFO] [stderr]     Checking instant v0.1.9
[INFO] [stderr]     Checking lock_api v0.4.2
[INFO] [stderr]     Checking rand_core v0.3.1
[INFO] [stderr]     Checking rand_jitter v0.1.3
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]     Checking rand_xorshift v0.1.1
[INFO] [stderr]     Checking rand_hc v0.1.0
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]     Checking parking_lot_core v0.8.1
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]     Checking parking_lot v0.11.1
[INFO] [stderr]    Compiling paste-impl v0.1.18
[INFO] [stderr]     Checking paste v0.1.18
[INFO] [stderr]    Compiling pyo3-derive-backend v0.12.4
[INFO] [stderr]    Compiling inventory-impl v0.1.10
[INFO] [stderr]    Compiling ghost v0.1.2
[INFO] [stderr]    Compiling ctor v0.1.16
[INFO] [stderr]    Compiling indoc-impl v0.3.6
[INFO] [stderr]     Checking indoc v0.3.6
[INFO] [stderr]    Compiling pyo3cls v0.12.4
[INFO] [stderr]     Checking fast_luhn v0.1.5 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(specialization)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]   = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stdout]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(specialization)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]   = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stdout]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: call to `.clone()` on a reference in this situation does nothing
[INFO] [stdout]   --> src/lib.rs:79:38
[INFO] [stdout]    |
[INFO] [stdout] 79 |         let mut valid_string = string.clone().to_string();
[INFO] [stdout]    |                                      ^^^^^^^^ help: remove this redundant call
[INFO] [stdout]    |
[INFO] [stdout]    = note: the type `str` does not implement `Clone`, so calling `clone` on `&str` copies the reference, which does not do anything and can be removed
[INFO] [stdout]    = note: `#[warn(noop_method_call)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: call to `.clone()` on a reference in this situation does nothing
[INFO] [stdout]   --> src/lib.rs:79:38
[INFO] [stdout]    |
[INFO] [stdout] 79 |         let mut valid_string = string.clone().to_string();
[INFO] [stdout]    |                                      ^^^^^^^^ help: remove this redundant call
[INFO] [stdout]    |
[INFO] [stdout]    = note: the type `str` does not implement `Clone`, so calling `clone` on `&str` copies the reference, which does not do anything and can be removed
[INFO] [stdout]    = note: `#[warn(noop_method_call)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 10.03s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: pyo3 v0.12.4, pyo3-derive-backend v0.12.4
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 3`
[INFO] running `Command { std: "docker" "inspect" "7a2ae1e27a06eefe5d886554f733e4efdb6fadedb1b073e7f094199a93909c54", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7a2ae1e27a06eefe5d886554f733e4efdb6fadedb1b073e7f094199a93909c54", kill_on_drop: false }`
[INFO] [stdout] 7a2ae1e27a06eefe5d886554f733e4efdb6fadedb1b073e7f094199a93909c54
