[INFO] cloning repository https://github.com/tarrall/chaosmarmoset [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tarrall/chaosmarmoset" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftarrall%2Fchaosmarmoset", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftarrall%2Fchaosmarmoset'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] 3e53563f1175d3903187bbcb81e4007033a88cfc [INFO] testing tarrall/chaosmarmoset against try#ce59db7a1b1b012fb2793c4641c1bdecad7a128b for pr-85530 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftarrall%2Fchaosmarmoset" "/workspace/builds/worker-1/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/tarrall/chaosmarmoset on toolchain ce59db7a1b1b012fb2793c4641c1bdecad7a128b [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ce59db7a1b1b012fb2793c4641c1bdecad7a128b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/tarrall/chaosmarmoset [INFO] finished tweaking git repo https://github.com/tarrall/chaosmarmoset [INFO] tweaked toml for git repo https://github.com/tarrall/chaosmarmoset written to /workspace/builds/worker-1/source/Cargo.toml [INFO] crate git repo https://github.com/tarrall/chaosmarmoset already has a lockfile, it will not be regenerated [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ce59db7a1b1b012fb2793c4641c1bdecad7a128b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+ce59db7a1b1b012fb2793c4641c1bdecad7a128b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 21373f6ebec37cf4168bae80020729063755937cca1e3afa9f9ef65ac181252f [INFO] running `Command { std: "docker" "start" "-a" "21373f6ebec37cf4168bae80020729063755937cca1e3afa9f9ef65ac181252f", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "21373f6ebec37cf4168bae80020729063755937cca1e3afa9f9ef65ac181252f", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "21373f6ebec37cf4168bae80020729063755937cca1e3afa9f9ef65ac181252f", kill_on_drop: false }` [INFO] [stdout] 21373f6ebec37cf4168bae80020729063755937cca1e3afa9f9ef65ac181252f [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+ce59db7a1b1b012fb2793c4641c1bdecad7a128b" "build" "--frozen" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] a6eadaae9d5c0e4c53bb8bb3b4a3119fd83eb1d82fe5fb644559c9cae4f5a680 [INFO] running `Command { std: "docker" "start" "-a" "a6eadaae9d5c0e4c53bb8bb3b4a3119fd83eb1d82fe5fb644559c9cae4f5a680", kill_on_drop: false }` [INFO] [stderr] Compiling autocfg v0.1.2 [INFO] [stderr] Compiling rand_core v0.4.0 [INFO] [stderr] Compiling cc v1.0.35 [INFO] [stderr] Compiling semver-parser v0.7.0 [INFO] [stderr] Compiling version_check v0.1.5 [INFO] [stderr] Compiling futures v0.1.26 [INFO] [stderr] Compiling smallvec v0.6.9 [INFO] [stderr] Compiling byteorder v1.3.1 [INFO] [stderr] Compiling scopeguard v0.3.3 [INFO] [stderr] Compiling syn v0.15.30 [INFO] [stderr] Compiling fnv v1.0.6 [INFO] [stderr] Compiling arrayvec v0.4.10 [INFO] [stderr] Compiling stable_deref_trait v1.1.1 [INFO] [stderr] Compiling pkg-config v0.3.14 [INFO] [stderr] Compiling itoa v0.4.3 [INFO] [stderr] Compiling siphasher v0.2.3 [INFO] [stderr] Compiling nodrop v0.1.13 [INFO] [stderr] Compiling lazycell v1.2.1 [INFO] [stderr] Compiling memoffset v0.2.1 [INFO] [stderr] Compiling build_const v0.2.1 [INFO] [stderr] Compiling rustc-demangle v0.1.13 [INFO] [stderr] Compiling bitflags v1.0.4 [INFO] [stderr] Compiling percent-encoding v1.0.1 [INFO] [stderr] Compiling openssl v0.10.20 [INFO] [stderr] Compiling regex v1.1.5 [INFO] [stderr] Compiling foreign-types-shared v0.1.1 [INFO] [stderr] Compiling httparse v1.3.3 [INFO] [stderr] Compiling failure_derive v0.1.5 [INFO] [stderr] Compiling ryu v0.2.7 [INFO] [stderr] Compiling indexmap v1.0.2 [INFO] [stderr] Compiling crc32fast v1.2.0 [INFO] [stderr] Compiling string v0.1.3 [INFO] [stderr] Compiling adler32 v1.0.3 [INFO] [stderr] Compiling try-lock v0.2.2 [INFO] [stderr] Compiling native-tls v0.2.2 [INFO] [stderr] Compiling openssl-probe v0.1.2 [INFO] [stderr] Compiling encoding_rs v0.8.17 [INFO] [stderr] Compiling unicode-width v0.1.5 [INFO] [stderr] Compiling unicode-segmentation v1.2.1 [INFO] [stderr] Compiling dtoa v0.4.3 [INFO] [stderr] Compiling crossbeam-utils v0.6.5 [INFO] [stderr] Compiling log v0.4.6 [INFO] [stderr] Compiling tokio-trace-core v0.1.0 [INFO] [stderr] Compiling try_from v0.3.2 [INFO] [stderr] Compiling foreign-types v0.3.2 [INFO] [stderr] Compiling owning_ref v0.4.0 [INFO] [stderr] Compiling rand_core v0.3.1 [INFO] [stderr] Compiling rand_jitter v0.1.3 [INFO] [stderr] Compiling miniz_oxide v0.2.1 [INFO] [stderr] Compiling semver v0.9.0 [INFO] [stderr] Compiling textwrap v0.11.0 [INFO] [stderr] Compiling unicode-normalization v0.1.8 [INFO] [stderr] Compiling rand_os v0.1.3 [INFO] [stderr] Compiling iovec v0.1.2 [INFO] [stderr] Compiling num_cpus v1.10.0 [INFO] [stderr] Compiling net2 v0.2.33 [INFO] [stderr] Compiling time v0.1.42 [INFO] [stderr] Compiling atty v0.2.11 [INFO] [stderr] Compiling rand_xorshift v0.1.1 [INFO] [stderr] Compiling rand_hc v0.1.0 [INFO] [stderr] Compiling rand_isaac v0.1.1 [INFO] [stderr] Compiling quote v0.6.12 [INFO] [stderr] Compiling aho-corasick v0.7.3 [INFO] [stderr] Compiling lock_api v0.1.5 [INFO] [stderr] Compiling heck v0.3.1 [INFO] [stderr] Compiling crc v1.8.1 [INFO] [stderr] Compiling clap v2.33.0 [INFO] [stderr] Compiling mio v0.6.16 [INFO] [stderr] Compiling crossbeam-queue v0.1.2 [INFO] [stderr] Compiling rustc_version v0.2.3 [INFO] [stderr] Compiling rand_pcg v0.1.2 [INFO] [stderr] Compiling rand_chacha v0.1.1 [INFO] [stderr] Compiling rand v0.6.5 [INFO] [stderr] Compiling backtrace v0.3.15 [INFO] [stderr] Compiling unicase v1.4.2 [INFO] [stderr] Compiling unicase v2.3.0 [INFO] [stderr] Compiling serde_json v1.0.39 [INFO] [stderr] Compiling crossbeam-epoch v0.7.1 [INFO] [stderr] Compiling bytes v0.4.12 [INFO] [stderr] Compiling base64 v0.10.1 [INFO] [stderr] Compiling parking_lot_core v0.4.0 [INFO] [stderr] Compiling tokio-executor v0.1.7 [INFO] [stderr] Compiling tokio-sync v0.1.4 [INFO] [stderr] Compiling futures-cpupool v0.1.8 [INFO] [stderr] Compiling want v0.0.6 [INFO] [stderr] Compiling openssl-sys v0.9.43 [INFO] [stderr] Compiling backtrace-sys v0.1.28 [INFO] [stderr] Compiling miniz_oxide_c_api v0.2.1 [INFO] [stderr] Compiling crossbeam-deque v0.7.1 [INFO] [stderr] Compiling mime v0.3.13 [INFO] [stderr] Compiling tokio-io v0.1.12 [INFO] [stderr] Compiling http v0.1.17 [INFO] [stderr] Compiling phf_shared v0.7.24 [INFO] [stderr] Compiling tokio-current-thread v0.1.6 [INFO] [stderr] Compiling tokio-timer v0.2.10 [INFO] [stderr] Compiling phf v0.7.24 [INFO] [stderr] Compiling idna v0.1.5 [INFO] [stderr] Compiling flate2 v1.0.7 [INFO] [stderr] Compiling url v1.7.2 [INFO] [stderr] Compiling phf_generator v0.7.24 [INFO] [stderr] Compiling tokio-threadpool v0.1.13 [INFO] [stderr] Compiling uuid v0.7.4 [INFO] [stderr] Compiling phf_codegen v0.7.24 [INFO] [stderr] Compiling error-chain v0.12.0 [INFO] [stderr] Compiling mime_guess v2.0.0-alpha.6 [INFO] [stderr] Compiling parking_lot v0.7.1 [INFO] [stderr] Compiling tokio-reactor v0.1.9 [INFO] [stderr] Compiling cookie v0.11.0 [INFO] [stderr] Compiling publicsuffix v1.5.2 [INFO] [stderr] Compiling serde_urlencoded v0.5.4 [INFO] [stderr] Compiling tokio-tcp v0.1.3 [INFO] [stderr] Compiling synstructure v0.10.1 [INFO] [stderr] Compiling tokio v0.1.18 [INFO] [stderr] Compiling h2 v0.1.18 [INFO] [stderr] Compiling serde_derive v1.0.90 [INFO] [stderr] Compiling structopt-derive v0.2.15 [INFO] [stderr] Compiling hyper v0.12.27 [INFO] [stderr] Compiling structopt v0.2.15 [INFO] [stderr] Compiling failure v0.1.5 [INFO] [stderr] Compiling hyper-tls v0.3.2 [INFO] [stderr] Compiling cookie_store v0.5.1 [INFO] [stderr] Compiling reqwest v0.9.14 [INFO] [stderr] Compiling chaosmarmoset v0.1.0 (/opt/rustwide/workdir) [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/main.rs:189:65 [INFO] [stdout] | [INFO] [stdout] 189 | fn web_client(url: String, sleepms: Duration) -> Result<(), Box> { [INFO] [stdout] | ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(bare_trait_objects)]` on by default [INFO] [stdout] = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition! [INFO] [stdout] = note: for more information, see issue #80165 [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable `x` is assigned to, but never used [INFO] [stdout] --> src/main.rs:90:13 [INFO] [stdout] | [INFO] [stdout] 90 | let x; [INFO] [stdout] | ^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` on by default [INFO] [stdout] = note: consider using `_x` instead [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: value assigned to `x` is never read [INFO] [stdout] --> src/main.rs:92:24 [INFO] [stdout] | [INFO] [stdout] 92 | Some(u) => x = web_client(u, sleepms), [INFO] [stdout] | ^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_assignments)]` on by default [INFO] [stdout] = help: maybe it is overwritten before being read? [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused `Result` that must be used [INFO] [stdout] --> src/main.rs:184:5 [INFO] [stdout] | [INFO] [stdout] 184 | std::io::copy(&mut stream, &mut std::io::stdout()); [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_must_use)]` on by default [INFO] [stdout] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] Finished dev [unoptimized + debuginfo] target(s) in 54.37s [INFO] [stdout] warning: 4 warnings emitted [INFO] [stdout] [INFO] [stdout] [INFO] running `Command { std: "docker" "inspect" "a6eadaae9d5c0e4c53bb8bb3b4a3119fd83eb1d82fe5fb644559c9cae4f5a680", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "a6eadaae9d5c0e4c53bb8bb3b4a3119fd83eb1d82fe5fb644559c9cae4f5a680", kill_on_drop: false }` [INFO] [stdout] a6eadaae9d5c0e4c53bb8bb3b4a3119fd83eb1d82fe5fb644559c9cae4f5a680 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+ce59db7a1b1b012fb2793c4641c1bdecad7a128b" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] 6e32b5e441d9392da3c4d4b1263529ef3b391683619f354c27a563eeb5da182a [INFO] running `Command { std: "docker" "start" "-a" "6e32b5e441d9392da3c4d4b1263529ef3b391683619f354c27a563eeb5da182a", kill_on_drop: false }` [INFO] [stderr] Blocking waiting for file lock on package cache [INFO] [stderr] Compiling chaosmarmoset v0.1.0 (/opt/rustwide/workdir) [INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stdout] --> src/main.rs:189:65 [INFO] [stdout] | [INFO] [stdout] 189 | fn web_client(url: String, sleepms: Duration) -> Result<(), Box> { [INFO] [stdout] | ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(bare_trait_objects)]` on by default [INFO] [stdout] = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition! [INFO] [stdout] = note: for more information, see issue #80165 [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable `x` is assigned to, but never used [INFO] [stdout] --> src/main.rs:90:13 [INFO] [stdout] | [INFO] [stdout] 90 | let x; [INFO] [stdout] | ^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` on by default [INFO] [stdout] = note: consider using `_x` instead [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: value assigned to `x` is never read [INFO] [stdout] --> src/main.rs:92:24 [INFO] [stdout] | [INFO] [stdout] 92 | Some(u) => x = web_client(u, sleepms), [INFO] [stdout] | ^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_assignments)]` on by default [INFO] [stdout] = help: maybe it is overwritten before being read? [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused `Result` that must be used [INFO] [stdout] --> src/main.rs:184:5 [INFO] [stdout] | [INFO] [stdout] 184 | std::io::copy(&mut stream, &mut std::io::stdout()); [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_must_use)]` on by default [INFO] [stdout] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: 4 warnings emitted [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] Finished test [unoptimized + debuginfo] target(s) in 1.74s [INFO] running `Command { std: "docker" "inspect" "6e32b5e441d9392da3c4d4b1263529ef3b391683619f354c27a563eeb5da182a", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "6e32b5e441d9392da3c4d4b1263529ef3b391683619f354c27a563eeb5da182a", kill_on_drop: false }` [INFO] [stdout] 6e32b5e441d9392da3c4d4b1263529ef3b391683619f354c27a563eeb5da182a [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+ce59db7a1b1b012fb2793c4641c1bdecad7a128b" "test" "--frozen", kill_on_drop: false }` [INFO] [stdout] 3225ab9355aaa3c83fe369682f4f61d9e61f0f5bf9c0e788390a56749c012dde [INFO] running `Command { std: "docker" "start" "-a" "3225ab9355aaa3c83fe369682f4f61d9e61f0f5bf9c0e788390a56749c012dde", kill_on_drop: false }` [INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated [INFO] [stderr] --> src/main.rs:189:65 [INFO] [stderr] | [INFO] [stderr] 189 | fn web_client(url: String, sleepms: Duration) -> Result<(), Box> { [INFO] [stderr] | ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error` [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(bare_trait_objects)]` on by default [INFO] [stderr] = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition! [INFO] [stderr] = note: for more information, see issue #80165 [INFO] [stderr] [INFO] [stderr] warning: variable `x` is assigned to, but never used [INFO] [stderr] --> src/main.rs:90:13 [INFO] [stderr] | [INFO] [stderr] 90 | let x; [INFO] [stderr] | ^ [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(unused_variables)]` on by default [INFO] [stderr] = note: consider using `_x` instead [INFO] [stderr] [INFO] [stderr] warning: value assigned to `x` is never read [INFO] [stderr] --> src/main.rs:92:24 [INFO] [stderr] | [INFO] [stderr] 92 | Some(u) => x = web_client(u, sleepms), [INFO] [stderr] | ^ [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(unused_assignments)]` on by default [INFO] [stderr] = help: maybe it is overwritten before being read? [INFO] [stderr] [INFO] [stderr] warning: unused `Result` that must be used [INFO] [stderr] --> src/main.rs:184:5 [INFO] [stderr] | [INFO] [stderr] 184 | std::io::copy(&mut stream, &mut std::io::stdout()); [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(unused_must_use)]` on by default [INFO] [stderr] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stderr] [INFO] [stderr] warning: 4 warnings emitted [INFO] [stderr] [INFO] [stderr] Finished test [unoptimized + debuginfo] target(s) in 0.15s [INFO] [stderr] Running unittests (/opt/rustwide/target/debug/deps/chaosmarmoset-2ab2e6c3d5ebf638) [INFO] [stdout] [INFO] [stdout] running 0 tests [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] running `Command { std: "docker" "inspect" "3225ab9355aaa3c83fe369682f4f61d9e61f0f5bf9c0e788390a56749c012dde", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "3225ab9355aaa3c83fe369682f4f61d9e61f0f5bf9c0e788390a56749c012dde", kill_on_drop: false }` [INFO] [stdout] 3225ab9355aaa3c83fe369682f4f61d9e61f0f5bf9c0e788390a56749c012dde