[INFO] fetching crate slice 0.0.4...
[INFO] testing slice-0.0.4 against 1.49.0 for beta-1.50-1
[INFO] extracting crate slice 0.0.4 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate slice 0.0.4 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", 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-3/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 926c1f2d4f441b48f824a6e1e7cac482eea60d27220373a9e71fd78842c608fa
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "926c1f2d4f441b48f824a6e1e7cac482eea60d27220373a9e71fd78842c608fa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "926c1f2d4f441b48f824a6e1e7cac482eea60d27220373a9e71fd78842c608fa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "926c1f2d4f441b48f824a6e1e7cac482eea60d27220373a9e71fd78842c608fa", kill_on_drop: false }`
[INFO] [stdout] 926c1f2d4f441b48f824a6e1e7cac482eea60d27220373a9e71fd78842c608fa
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f700c622551c8c4746dd5d6c1f109d729bd9b1101b713caa8d8bb52611d50901
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "f700c622551c8c4746dd5d6c1f109d729bd9b1101b713caa8d8bb52611d50901", kill_on_drop: false }`
[INFO] [stderr]    Compiling slice v0.0.4 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.61s
[INFO] running `Command { std: "docker" "inspect" "f700c622551c8c4746dd5d6c1f109d729bd9b1101b713caa8d8bb52611d50901", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f700c622551c8c4746dd5d6c1f109d729bd9b1101b713caa8d8bb52611d50901", kill_on_drop: false }`
[INFO] [stdout] f700c622551c8c4746dd5d6c1f109d729bd9b1101b713caa8d8bb52611d50901
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 56e866b96033ad47d1d5d05e41e5e78bc46829a5d5b144e4b45e4b26ce8f7ceb
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "56e866b96033ad47d1d5d05e41e5e78bc46829a5d5b144e4b45e4b26ce8f7ceb", kill_on_drop: false }`
[INFO] [stderr]    Compiling slice v0.0.4 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.68s
[INFO] running `Command { std: "docker" "inspect" "56e866b96033ad47d1d5d05e41e5e78bc46829a5d5b144e4b45e4b26ce8f7ceb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "56e866b96033ad47d1d5d05e41e5e78bc46829a5d5b144e4b45e4b26ce8f7ceb", kill_on_drop: false }`
[INFO] [stdout] 56e866b96033ad47d1d5d05e41e5e78bc46829a5d5b144e4b45e4b26ce8f7ceb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 59d8a64a38cad80f29791db9060b3f83abfd6dbc778005296ab1df51e3c28183
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "59d8a64a38cad80f29791db9060b3f83abfd6dbc778005296ab1df51e3c28183", kill_on_drop: false }`
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/slice-1b08c6dcfe6f864a
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests slice
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] running 2 tests
[INFO] [stdout] test src/lib.rs - (line 10) ... FAILED
[INFO] [stdout] test src/lib.rs - IoSlice (line 56) ... FAILED
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout] 
[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 `Try`)
[INFO] [stdout]   --> src/lib.rs:14:14
[INFO] [stdout]    |
[INFO] [stdout] 3  | / fn main() {
[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 | | }
[INFO] [stdout]    | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `Try` is not implemented for `()`
[INFO] [stdout]    = note: required by `from_error`
[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 - 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 `Try`)
[INFO] [stdout]   --> src/lib.rs:60:14
[INFO] [stdout]    |
[INFO] [stdout] 3  | / fn main() {
[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 | | }
[INFO] [stdout]    | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `Try` is not implemented for `()`
[INFO] [stdout]    = note: required by `from_error`
[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
[INFO] [stdout] 
[INFO] [stderr] error: test failed, to rerun pass '--doc'
[INFO] running `Command { std: "docker" "inspect" "59d8a64a38cad80f29791db9060b3f83abfd6dbc778005296ab1df51e3c28183", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "59d8a64a38cad80f29791db9060b3f83abfd6dbc778005296ab1df51e3c28183", kill_on_drop: false }`
[INFO] [stdout] 59d8a64a38cad80f29791db9060b3f83abfd6dbc778005296ab1df51e3c28183