[INFO] fetching crate serbo-mc 0.1.0...
[INFO] checking serbo-mc-0.1.0 against try#998b6603a58e47f42ccce7a67943234e96b6839e for pr-143170
[INFO] extracting crate serbo-mc 0.1.0 into /workspace/builds/worker-2-tc2/source
[INFO] started tweaking crates.io crate serbo-mc 0.1.0
[INFO] finished tweaking crates.io crate serbo-mc 0.1.0
[INFO] tweaked toml for crates.io crate serbo-mc 0.1.0 written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate serbo-mc 0.1.0 on toolchain 998b6603a58e47f42ccce7a67943234e96b6839e
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+998b6603a58e47f42ccce7a67943234e96b6839e" "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" "+998b6603a58e47f42ccce7a67943234e96b6839e" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 14 packages to latest compatible versions
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+998b6603a58e47f42ccce7a67943234e96b6839e" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+998b6603a58e47f42ccce7a67943234e96b6839e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7f0f5bf68dad4540e6427dc6100b800c1de6289e86388309308f56d7251bc61c
[INFO] running `Command { std: "docker" "start" "-a" "7f0f5bf68dad4540e6427dc6100b800c1de6289e86388309308f56d7251bc61c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7f0f5bf68dad4540e6427dc6100b800c1de6289e86388309308f56d7251bc61c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7f0f5bf68dad4540e6427dc6100b800c1de6289e86388309308f56d7251bc61c", kill_on_drop: false }`
[INFO] [stdout] 7f0f5bf68dad4540e6427dc6100b800c1de6289e86388309308f56d7251bc61c
[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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+998b6603a58e47f42ccce7a67943234e96b6839e" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 33744393607a78bbadf5ca9919cc673fe897fe28d50ae6033ce613e35206f2d4
[INFO] running `Command { std: "docker" "start" "-a" "33744393607a78bbadf5ca9919cc673fe897fe28d50ae6033ce613e35206f2d4", kill_on_drop: false }`
[INFO] [stderr]     Checking same-file v1.0.6
[INFO] [stderr]     Checking walkdir v2.5.0
[INFO] [stderr]     Checking copy_dir v0.1.3
[INFO] [stderr]     Checking serbo-mc v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/lib.rs:284:11
[INFO] [stdout]     |
[INFO] [stdout] 284 |           writeln!(writer, "{}", x);
[INFO] [stdout]     |           ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: this warning originates in the macro `writeln` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/lib.rs:285:11
[INFO] [stdout]     |
[INFO] [stdout] 285 |           writer.flush();
[INFO] [stdout]     |           ^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 285 |           let _ = writer.flush();
[INFO] [stdout]     |           +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/lib.rs:293:5
[INFO] [stdout]     |
[INFO] [stdout] 293 |     &self.servers.insert(id.to_string(), serv_inst);
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 293 |     let _ = &self.servers.insert(id.to_string(), serv_inst);
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/lib.rs:303:7
[INFO] [stdout]     |
[INFO] [stdout] 303 |       inst.stdout_join.take().unwrap().join();
[INFO] [stdout]     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 303 |       let _ = inst.stdout_join.take().unwrap().join();
[INFO] [stdout]     |       +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/lib.rs:304:7
[INFO] [stdout]     |
[INFO] [stdout] 304 |       inst.stdin_join.take().unwrap().join();
[INFO] [stdout]     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 304 |       let _ = inst.stdin_join.take().unwrap().join();
[INFO] [stdout]     |       +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/lib.rs:284:11
[INFO] [stdout]     |
[INFO] [stdout] 284 |           writeln!(writer, "{}", x);
[INFO] [stdout]     |           ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: this warning originates in the macro `writeln` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/lib.rs:285:11
[INFO] [stdout]     |
[INFO] [stdout] 285 |           writer.flush();
[INFO] [stdout]     |           ^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 285 |           let _ = writer.flush();
[INFO] [stdout]     |           +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/lib.rs:293:5
[INFO] [stdout]     |
[INFO] [stdout] 293 |     &self.servers.insert(id.to_string(), serv_inst);
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 293 |     let _ = &self.servers.insert(id.to_string(), serv_inst);
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/lib.rs:303:7
[INFO] [stdout]     |
[INFO] [stdout] 303 |       inst.stdout_join.take().unwrap().join();
[INFO] [stdout]     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 303 |       let _ = inst.stdout_join.take().unwrap().join();
[INFO] [stdout]     |       +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/lib.rs:304:7
[INFO] [stdout]     |
[INFO] [stdout] 304 |       inst.stdin_join.take().unwrap().join();
[INFO] [stdout]     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 304 |       let _ = inst.stdin_join.take().unwrap().join();
[INFO] [stdout]     |       +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.65s
[INFO] running `Command { std: "docker" "inspect" "33744393607a78bbadf5ca9919cc673fe897fe28d50ae6033ce613e35206f2d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "33744393607a78bbadf5ca9919cc673fe897fe28d50ae6033ce613e35206f2d4", kill_on_drop: false }`
[INFO] [stdout] 33744393607a78bbadf5ca9919cc673fe897fe28d50ae6033ce613e35206f2d4