[INFO] fetching crate observables 0.1.0...
[INFO] checking observables-0.1.0 against master#cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c for pr-143170
[INFO] extracting crate observables 0.1.0 into /workspace/builds/worker-2-tc1/source
[INFO] started tweaking crates.io crate observables 0.1.0
[INFO] finished tweaking crates.io crate observables 0.1.0
[INFO] tweaked toml for crates.io crate observables 0.1.0 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate observables 0.1.0 on toolchain cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "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" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 42 packages to latest compatible versions
[INFO] [stderr]       Adding async-channel v1.9.0 (available: v2.3.1)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded gensym v0.1.1
[INFO] [stderr]   Downloaded futures-signals v0.3.34
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] bc36be0a3bd8f9d98db85e58b349ed5e6a6e4455594d22aa5e5314c1d3acac33
[INFO] running `Command { std: "docker" "start" "-a" "bc36be0a3bd8f9d98db85e58b349ed5e6a6e4455594d22aa5e5314c1d3acac33", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bc36be0a3bd8f9d98db85e58b349ed5e6a6e4455594d22aa5e5314c1d3acac33", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bc36be0a3bd8f9d98db85e58b349ed5e6a6e4455594d22aa5e5314c1d3acac33", kill_on_drop: false }`
[INFO] [stdout] bc36be0a3bd8f9d98db85e58b349ed5e6a6e4455594d22aa5e5314c1d3acac33
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 46b214d2191c969516bd9135784bf072d7f772a040e9718848a090270122267a
[INFO] running `Command { std: "docker" "start" "-a" "46b214d2191c969516bd9135784bf072d7f772a040e9718848a090270122267a", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.95
[INFO] [stderr]    Compiling libc v0.2.174
[INFO] [stderr]    Compiling getrandom v0.3.3
[INFO] [stderr]    Compiling cfg-if v1.0.1
[INFO] [stderr]    Compiling crossbeam-utils v0.8.21
[INFO] [stderr]    Compiling serde v1.0.219
[INFO] [stderr]     Checking discard v1.0.4
[INFO] [stderr]     Checking event-listener v2.5.3
[INFO] [stderr]     Checking waker-fn v1.2.0
[INFO] [stderr]     Checking futures-channel v0.3.31
[INFO] [stderr]     Checking concurrent-queue v2.5.0
[INFO] [stderr]     Checking async-channel v1.9.0
[INFO] [stderr]    Compiling quote v1.0.40
[INFO] [stderr]    Compiling syn v2.0.104
[INFO] [stderr]    Compiling uuid v1.17.0
[INFO] [stderr]    Compiling futures-macro v0.3.31
[INFO] [stderr]    Compiling serde_derive v1.0.219
[INFO] [stderr]    Compiling pin-project-internal v1.1.10
[INFO] [stderr]    Compiling gensym v0.1.1
[INFO] [stderr]     Checking futures-util v0.3.31
[INFO] [stderr]     Checking pin-project v1.1.10
[INFO] [stderr]     Checking futures-signals v0.3.34
[INFO] [stderr]     Checking observables v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: struct `NoChange` is never constructed
[INFO] [stdout]  --> src/impls/mod.rs:4:12
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub struct NoChange<T>(pub T);
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: using `.deref()` on a double reference, which returns `&T` instead of dereferencing the inner type
[INFO] [stdout]   --> src/lib.rs:41:45
[INFO] [stdout]    |
[INFO] [stdout] 41 |             ObservableBorrow::Borrow(x) => x.deref(),
[INFO] [stdout]    |                                             ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(suspicious_double_ref_op)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `NoChange` is never constructed
[INFO] [stdout]  --> src/impls/mod.rs:4:12
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub struct NoChange<T>(pub T);
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: using `.deref()` on a double reference, which returns `&T` instead of dereferencing the inner type
[INFO] [stdout]   --> src/lib.rs:41:45
[INFO] [stdout]    |
[INFO] [stdout] 41 |             ObservableBorrow::Borrow(x) => x.deref(),
[INFO] [stdout]    |                                             ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(suspicious_double_ref_op)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 14.96s
[INFO] running `Command { std: "docker" "inspect" "46b214d2191c969516bd9135784bf072d7f772a040e9718848a090270122267a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "46b214d2191c969516bd9135784bf072d7f772a040e9718848a090270122267a", kill_on_drop: false }`
[INFO] [stdout] 46b214d2191c969516bd9135784bf072d7f772a040e9718848a090270122267a