[INFO] fetching crate switchable 0.1.0...
[INFO] checking switchable-0.1.0 against master#dfd7b8d03fb93d0e03147d28b3be6d93260fa94d for pr-87050
[INFO] extracting crate switchable 0.1.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate switchable 0.1.0 on toolchain dfd7b8d03fb93d0e03147d28b3be6d93260fa94d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate switchable 0.1.0
[INFO] finished tweaking crates.io crate switchable 0.1.0
[INFO] tweaked toml for crates.io crate switchable 0.1.0 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate switchable 0.1.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded proc-macro2 v1.0.13
[INFO] [stderr]   Downloaded libc v0.2.70
[INFO] [stderr]   Downloaded serde_json v1.0.53
[INFO] [stderr]   Downloaded quote v1.0.5
[INFO] [stderr]   Downloaded syn v1.0.22
[INFO] [stderr]   Downloaded tear v0.2.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d69b0f8fde8a9b2d125a4bad2797698eb59523c2cc73e8ecc40dfec386cfe0ed
[INFO] running `Command { std: "docker" "start" "-a" "d69b0f8fde8a9b2d125a4bad2797698eb59523c2cc73e8ecc40dfec386cfe0ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d69b0f8fde8a9b2d125a4bad2797698eb59523c2cc73e8ecc40dfec386cfe0ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d69b0f8fde8a9b2d125a4bad2797698eb59523c2cc73e8ecc40dfec386cfe0ed", kill_on_drop: false }`
[INFO] [stdout] d69b0f8fde8a9b2d125a4bad2797698eb59523c2cc73e8ecc40dfec386cfe0ed
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8d31a0b8df0af216e407bcaf285a867ff7f75f48bff5fd136b7f66fd296111a4
[INFO] running `Command { std: "docker" "start" "-a" "8d31a0b8df0af216e407bcaf285a867ff7f75f48bff5fd136b7f66fd296111a4", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.13
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.22
[INFO] [stderr]    Compiling libc v0.2.70
[INFO] [stderr]    Compiling serde v1.0.110
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking tear v0.2.0
[INFO] [stderr]     Checking getopts v0.2.21
[INFO] [stderr]     Checking thread_local v1.0.1
[INFO] [stderr]     Checking regex v1.3.7
[INFO] [stderr]    Compiling quote v1.0.5
[INFO] [stderr]     Checking dirs-sys v0.3.4
[INFO] [stderr]     Checking dirs v2.0.2
[INFO] [stderr]    Compiling serde_derive v1.0.110
[INFO] [stderr]    Compiling thiserror-impl v1.0.19
[INFO] [stderr]     Checking thiserror v1.0.19
[INFO] [stderr]     Checking toml v0.5.6
[INFO] [stderr]     Checking serde_json v1.0.53
[INFO] [stderr]     Checking switchable v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0034]: multiple applicable items in scope
[INFO] [stdout]   --> src/app.rs:79:6
[INFO] [stdout]    |
[INFO] [stdout] 79 |                 .reduce(|a, b| format!("{} {}", a, b)).unwrap(); // We checked is_empty
[INFO] [stdout]    |                  ^^^^^^ multiple `reduce` found
[INFO] [stdout]    |
[INFO] [stdout] note: candidate #1 is defined in an impl of the trait `slang::IterExt` for the type `Me`
[INFO] [stdout]   --> src/slang.rs:19:2
[INFO] [stdout]    |
[INFO] [stdout] 19 |     fn reduce (mut self, f :impl FnMut(T, T) -> T) -> Option<T> {
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    = note: candidate #2 is defined in an impl of the trait `Iterator` for the type `std::iter::Map<I, F>`
[INFO] [stdout] help: disambiguate the associated function for candidate #1
[INFO] [stdout]    |
[INFO] [stdout] 77 |             let aliases_str = slang::IterExt::reduce(to_rm.iter()
[INFO] [stdout] 78 |                 .map(|v| format!("'{}'", v)), |a, b| format!("{} {}", a, b)).unwrap(); // We checked is_empty
[INFO] [stdout]    |
[INFO] [stdout] help: disambiguate the associated function for candidate #2
[INFO] [stdout]    |
[INFO] [stdout] 77 |             let aliases_str = Iterator::reduce(to_rm.iter()
[INFO] [stdout] 78 |                 .map(|v| format!("'{}'", v)), |a, b| format!("{} {}", a, b)).unwrap(); // We checked is_empty
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0034`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `switchable`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error[E0034]: multiple applicable items in scope
[INFO] [stdout]   --> src/app.rs:79:6
[INFO] [stdout]    |
[INFO] [stdout] 79 |                 .reduce(|a, b| format!("{} {}", a, b)).unwrap(); // We checked is_empty
[INFO] [stdout]    |                  ^^^^^^ multiple `reduce` found
[INFO] [stdout]    |
[INFO] [stdout] note: candidate #1 is defined in an impl of the trait `slang::IterExt` for the type `Me`
[INFO] [stdout]   --> src/slang.rs:19:2
[INFO] [stdout]    |
[INFO] [stdout] 19 |     fn reduce (mut self, f :impl FnMut(T, T) -> T) -> Option<T> {
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    = note: candidate #2 is defined in an impl of the trait `Iterator` for the type `std::iter::Map<I, F>`
[INFO] [stdout] help: disambiguate the associated function for candidate #1
[INFO] [stdout]    |
[INFO] [stdout] 77 |             let aliases_str = slang::IterExt::reduce(to_rm.iter()
[INFO] [stdout] 78 |                 .map(|v| format!("'{}'", v)), |a, b| format!("{} {}", a, b)).unwrap(); // We checked is_empty
[INFO] [stdout]    |
[INFO] [stdout] help: disambiguate the associated function for candidate #2
[INFO] [stdout]    |
[INFO] [stdout] 77 |             let aliases_str = Iterator::reduce(to_rm.iter()
[INFO] [stdout] 78 |                 .map(|v| format!("'{}'", v)), |a, b| format!("{} {}", a, b)).unwrap(); // We checked is_empty
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0034`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "8d31a0b8df0af216e407bcaf285a867ff7f75f48bff5fd136b7f66fd296111a4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8d31a0b8df0af216e407bcaf285a867ff7f75f48bff5fd136b7f66fd296111a4", kill_on_drop: false }`
[INFO] [stdout] 8d31a0b8df0af216e407bcaf285a867ff7f75f48bff5fd136b7f66fd296111a4