[INFO] fetching crate slice 0.0.4...
[INFO] testing slice-0.0.4 against 1.54.0 for beta-1.55-1
[INFO] extracting crate slice 0.0.4 into /workspace/builds/worker-75/source
[INFO] validating manifest of crates.io crate slice 0.0.4 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate slice 0.0.4
[INFO] finished tweaking crates.io crate slice 0.0.4
[INFO] tweaked toml for crates.io crate slice 0.0.4 written to /workspace/builds/worker-75/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "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" "+1.54.0" "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-75/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-75/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 495627f54453e3be653529354b72e0f719aceb32690313be57cf4f2a1d09a7a4
[INFO] running `Command { std: "docker" "start" "-a" "495627f54453e3be653529354b72e0f719aceb32690313be57cf4f2a1d09a7a4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "495627f54453e3be653529354b72e0f719aceb32690313be57cf4f2a1d09a7a4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "495627f54453e3be653529354b72e0f719aceb32690313be57cf4f2a1d09a7a4", kill_on_drop: false }`
[INFO] [stdout] 495627f54453e3be653529354b72e0f719aceb32690313be57cf4f2a1d09a7a4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-75/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-75/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=warn" "-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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b54a6575cdff321118878cbb1b00dd3ebc90149bf11b8259f62ef4e6f0547902
[INFO] running `Command { std: "docker" "start" "-a" "b54a6575cdff321118878cbb1b00dd3ebc90149bf11b8259f62ef4e6f0547902", kill_on_drop: false }`
[INFO] [stderr]    Compiling slice v0.0.4 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.84s
[INFO] running `Command { std: "docker" "inspect" "b54a6575cdff321118878cbb1b00dd3ebc90149bf11b8259f62ef4e6f0547902", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b54a6575cdff321118878cbb1b00dd3ebc90149bf11b8259f62ef4e6f0547902", kill_on_drop: false }`
[INFO] [stdout] b54a6575cdff321118878cbb1b00dd3ebc90149bf11b8259f62ef4e6f0547902
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-75/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-75/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=warn" "-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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 80d8f5be4491c1f8db34cf30049ff36b009bb850c746f55022c9963de58011c5
[INFO] running `Command { std: "docker" "start" "-a" "80d8f5be4491c1f8db34cf30049ff36b009bb850c746f55022c9963de58011c5", kill_on_drop: false }`
[INFO] [stderr]    Compiling slice v0.0.4 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.54s
[INFO] running `Command { std: "docker" "inspect" "80d8f5be4491c1f8db34cf30049ff36b009bb850c746f55022c9963de58011c5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "80d8f5be4491c1f8db34cf30049ff36b009bb850c746f55022c9963de58011c5", kill_on_drop: false }`
[INFO] [stdout] 80d8f5be4491c1f8db34cf30049ff36b009bb850c746f55022c9963de58011c5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-75/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-75/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=warn" "-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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 66f80044770987c59d8021aca16b626389c858dc1dff9b600c2748530991a062
[INFO] running `Command { std: "docker" "start" "-a" "66f80044770987c59d8021aca16b626389c858dc1dff9b600c2748530991a062", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.07s
[INFO] [stdout] running 0 tests
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/slice-9a286b0fc28cc384)
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests slice
[INFO] [stdout] 
[INFO] [stdout] running 2 tests
[INFO] [stdout] test src/lib.rs - IoSlice (line 56) ... FAILED
[INFO] [stderr] error: test failed, to rerun pass '--doc'
[INFO] [stdout] test src/lib.rs - (line 10) ... FAILED
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout] 
[INFO] [stdout] ---- src/lib.rs - IoSlice (line 56) stdout ----
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]   --> src/lib.rs:60:48
[INFO] [stdout]    |
[INFO] [stdout] 3  |   fn main() { #[allow(non_snake_case)] fn _doctest_main_src_lib_rs_56_0() {
[INFO] [stdout]    |  ______________________________________-
[INFO] [stdout] 4  | | use { std::fs::File, slice::IoSlice };
[INFO] [stdout] 5  | |
[INFO] [stdout] 6  | |
[INFO] [stdout] 7  | | let source = File::open("/home/annie/data.png")?;
[INFO] [stdout]    | |                                                ^ cannot use the `?` operator in a function that returns `()`
[INFO] [stdout] ...  |
[INFO] [stdout] 27 | | //
[INFO] [stdout] 28 | | } _doctest_main_src_lib_rs_56_0() }
[INFO] [stdout]    | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
[INFO] [stdout]    = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] Couldn't compile the test.
[INFO] [stdout] ---- src/lib.rs - (line 10) stdout ----
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]   --> src/lib.rs:14:48
[INFO] [stdout]    |
[INFO] [stdout] 3  |   fn main() { #[allow(non_snake_case)] fn _doctest_main_src_lib_rs_10_0() {
[INFO] [stdout]    |  ______________________________________-
[INFO] [stdout] 4  | | use { std::fs::File, slice::IoSlice };
[INFO] [stdout] 5  | |
[INFO] [stdout] 6  | |
[INFO] [stdout] 7  | | let source = File::open("/home/annie/data.png")?;
[INFO] [stdout]    | |                                                ^ cannot use the `?` operator in a function that returns `()`
[INFO] [stdout] ...  |
[INFO] [stdout] 27 | | //
[INFO] [stdout] 28 | | } _doctest_main_src_lib_rs_10_0() }
[INFO] [stdout]    | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
[INFO] [stdout]    = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] Couldn't compile the test.
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout]     src/lib.rs - (line 10)
[INFO] [stdout]     src/lib.rs - IoSlice (line 56)
[INFO] [stdout] 
[INFO] [stdout] test result: FAILED. 0 passed; 2 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.17s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "66f80044770987c59d8021aca16b626389c858dc1dff9b600c2748530991a062", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "66f80044770987c59d8021aca16b626389c858dc1dff9b600c2748530991a062", kill_on_drop: false }`
[INFO] [stdout] 66f80044770987c59d8021aca16b626389c858dc1dff9b600c2748530991a062
