[INFO] cloning repository https://github.com/ijanos/rustup_prompt_helper
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ijanos/rustup_prompt_helper" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fijanos%2Frustup_prompt_helper", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fijanos%2Frustup_prompt_helper'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a0bbef9d33d0e2451eeff0e910990d7aa1d0641a
[INFO] testing ijanos/rustup_prompt_helper against beta-2022-04-10 for beta-1.61-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fijanos%2Frustup_prompt_helper" "/workspace/builds/worker-8/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ijanos/rustup_prompt_helper on toolchain beta-2022-04-10
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-04-10" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ijanos/rustup_prompt_helper
[INFO] finished tweaking git repo https://github.com/ijanos/rustup_prompt_helper
[INFO] tweaked toml for git repo https://github.com/ijanos/rustup_prompt_helper written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/ijanos/rustup_prompt_helper already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-04-10" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-04-10" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] cff78b5f3b1044f3bbbbbb907b4b4ad5bb1b9bbe899968471c4c18a8ca68a7a7
[INFO] running `Command { std: "docker" "start" "-a" "cff78b5f3b1044f3bbbbbb907b4b4ad5bb1b9bbe899968471c4c18a8ca68a7a7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cff78b5f3b1044f3bbbbbb907b4b4ad5bb1b9bbe899968471c4c18a8ca68a7a7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cff78b5f3b1044f3bbbbbb907b4b4ad5bb1b9bbe899968471c4c18a8ca68a7a7", kill_on_drop: false }`
[INFO] [stdout] cff78b5f3b1044f3bbbbbb907b4b4ad5bb1b9bbe899968471c4c18a8ca68a7a7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-04-10" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 771ab2485c13060e8384f07820cd1ac2d4da38248c686d88445ba4fbdc1f4752
[INFO] running `Command { std: "docker" "start" "-a" "771ab2485c13060e8384f07820cd1ac2d4da38248c686d88445ba4fbdc1f4752", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.2
[INFO] [stderr]    Compiling toml v0.4.0
[INFO] [stderr]    Compiling rustup_prompt_helper v1.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:20:5
[INFO] [stdout]    |
[INFO] [stdout] 20 |     try!(file.read_to_string(&mut buffer).map_err(|_| "cannot read settings.toml"));
[INFO] [stdout]    |     ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:14:29
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut settings_path = try!(env::home_dir().ok_or("cannot get home directory"));
[INFO] [stdout]    |                             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:17:20
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let mut file = try!(File::open(&settings_path).map_err(|_| "cannot open settings.toml file"));
[INFO] [stdout]    |                    ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |         try!((&buffer).parse::<Value>().map_err(|_| "cannot parse settings.toml as toml"));
[INFO] [stdout]    |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:24:19
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let default = try!(value.get("default_toolchain")
[INFO] [stdout]    |                   ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:27:21
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let overrides = try!(value.get("overrides")
[INFO] [stdout]    |                     ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:35:15
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let cwd = try!(env::current_dir().map_err(|_| "cannot get working directory"));
[INFO] [stdout]    |               ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:36:15
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let cwd = try!(cwd.to_str().ok_or("cannot convert working directory to string"));
[INFO] [stdout]    |               ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:37:32
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let (default, overrides) = try!(read_settings());
[INFO] [stdout]    |                                ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:41:29
[INFO] [stdout]    |
[INFO] [stdout] 41 |             let toolchain = try!(strip_toolchain(toolchain).ok_or("Can not parse settings.toml"));
[INFO] [stdout]    |                             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated function `std::env::home_dir`: This function's behavior is unexpected and probably not what you want. Consider using a crate from crates.io instead.
[INFO] [stdout]   --> src/main.rs:14:39
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut settings_path = try!(env::home_dir().ok_or("cannot get home directory"));
[INFO] [stdout]    |                                       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 11 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 9.81s
[INFO] running `Command { std: "docker" "inspect" "771ab2485c13060e8384f07820cd1ac2d4da38248c686d88445ba4fbdc1f4752", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "771ab2485c13060e8384f07820cd1ac2d4da38248c686d88445ba4fbdc1f4752", kill_on_drop: false }`
[INFO] [stdout] 771ab2485c13060e8384f07820cd1ac2d4da38248c686d88445ba4fbdc1f4752
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-04-10" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7c1a14faa394b00b6e033b1fb54d092c4db2ea0acb21abcaef9194f6abcdb922
[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" "7c1a14faa394b00b6e033b1fb54d092c4db2ea0acb21abcaef9194f6abcdb922", kill_on_drop: false }`
[INFO] [stderr]    Compiling rustup_prompt_helper v1.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:20:5
[INFO] [stdout]    |
[INFO] [stdout] 20 |     try!(file.read_to_string(&mut buffer).map_err(|_| "cannot read settings.toml"));
[INFO] [stdout]    |     ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:14:29
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut settings_path = try!(env::home_dir().ok_or("cannot get home directory"));
[INFO] [stdout]    |                             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:17:20
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let mut file = try!(File::open(&settings_path).map_err(|_| "cannot open settings.toml file"));
[INFO] [stdout]    |                    ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |         try!((&buffer).parse::<Value>().map_err(|_| "cannot parse settings.toml as toml"));
[INFO] [stdout]    |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:24:19
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let default = try!(value.get("default_toolchain")
[INFO] [stdout]    |                   ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:27:21
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let overrides = try!(value.get("overrides")
[INFO] [stdout]    |                     ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:35:15
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let cwd = try!(env::current_dir().map_err(|_| "cannot get working directory"));
[INFO] [stdout]    |               ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:36:15
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let cwd = try!(cwd.to_str().ok_or("cannot convert working directory to string"));
[INFO] [stdout]    |               ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:37:32
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let (default, overrides) = try!(read_settings());
[INFO] [stdout]    |                                ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/main.rs:41:29
[INFO] [stdout]    |
[INFO] [stdout] 41 |             let toolchain = try!(strip_toolchain(toolchain).ok_or("Can not parse settings.toml"));
[INFO] [stdout]    |                             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated function `std::env::home_dir`: This function's behavior is unexpected and probably not what you want. Consider using a crate from crates.io instead.
[INFO] [stdout]   --> src/main.rs:14:39
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut settings_path = try!(env::home_dir().ok_or("cannot get home directory"));
[INFO] [stdout]    |                                       ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 11 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.96s
[INFO] [stderr]   Executable unittests src/main.rs (/opt/rustwide/target/debug/deps/rustup_prompt_helper-6838e736f3d76903)
[INFO] running `Command { std: "docker" "inspect" "7c1a14faa394b00b6e033b1fb54d092c4db2ea0acb21abcaef9194f6abcdb922", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7c1a14faa394b00b6e033b1fb54d092c4db2ea0acb21abcaef9194f6abcdb922", kill_on_drop: false }`
[INFO] [stdout] 7c1a14faa394b00b6e033b1fb54d092c4db2ea0acb21abcaef9194f6abcdb922
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-04-10" "test" "--frozen", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 94815cb707d48d56b5bc7c12d205c08dcc3cb1bd8488c9f83409512b46b32218
[INFO] running `Command { std: "docker" "start" "-a" "94815cb707d48d56b5bc7c12d205c08dcc3cb1bd8488c9f83409512b46b32218", kill_on_drop: false }`
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/main.rs:20:5
[INFO] [stderr]    |
[INFO] [stderr] 20 |     try!(file.read_to_string(&mut buffer).map_err(|_| "cannot read settings.toml"));
[INFO] [stderr]    |     ^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(deprecated)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/main.rs:14:29
[INFO] [stderr]    |
[INFO] [stderr] 14 |     let mut settings_path = try!(env::home_dir().ok_or("cannot get home directory"));
[INFO] [stderr]    |                             ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/main.rs:17:20
[INFO] [stderr]    |
[INFO] [stderr] 17 |     let mut file = try!(File::open(&settings_path).map_err(|_| "cannot open settings.toml file"));
[INFO] [stderr]    |                    ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/main.rs:23:9
[INFO] [stderr]    |
[INFO] [stderr] 23 |         try!((&buffer).parse::<Value>().map_err(|_| "cannot parse settings.toml as toml"));
[INFO] [stderr]    |         ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/main.rs:24:19
[INFO] [stderr]    |
[INFO] [stderr] 24 |     let default = try!(value.get("default_toolchain")
[INFO] [stderr]    |                   ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/main.rs:27:21
[INFO] [stderr]    |
[INFO] [stderr] 27 |     let overrides = try!(value.get("overrides")
[INFO] [stderr]    |                     ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/main.rs:35:15
[INFO] [stderr]    |
[INFO] [stderr] 35 |     let cwd = try!(env::current_dir().map_err(|_| "cannot get working directory"));
[INFO] [stderr]    |               ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/main.rs:36:15
[INFO] [stderr]    |
[INFO] [stderr] 36 |     let cwd = try!(cwd.to_str().ok_or("cannot convert working directory to string"));
[INFO] [stderr]    |               ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/main.rs:37:32
[INFO] [stderr]    |
[INFO] [stderr] 37 |     let (default, overrides) = try!(read_settings());
[INFO] [stderr]    |                                ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/main.rs:41:29
[INFO] [stderr]    |
[INFO] [stderr] 41 |             let toolchain = try!(strip_toolchain(toolchain).ok_or("Can not parse settings.toml"));
[INFO] [stderr]    |                             ^^^
[INFO] [stderr] 
[INFO] [stdout] 
[INFO] [stderr] warning: use of deprecated function `std::env::home_dir`: This function's behavior is unexpected and probably not what you want. Consider using a crate from crates.io instead.
[INFO] [stdout] running 0 tests
[INFO] [stderr]   --> src/main.rs:14:39
[INFO] [stdout] 
[INFO] [stderr]    |
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stderr] 14 |     let mut settings_path = try!(env::home_dir().ok_or("cannot get home directory"));
[INFO] [stdout] 
[INFO] [stderr]    |                                       ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `rustup_prompt_helper` (bin "rustup_prompt_helper" test) generated 11 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/deps/rustup_prompt_helper-6838e736f3d76903)
[INFO] running `Command { std: "docker" "inspect" "94815cb707d48d56b5bc7c12d205c08dcc3cb1bd8488c9f83409512b46b32218", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "94815cb707d48d56b5bc7c12d205c08dcc3cb1bd8488c9f83409512b46b32218", kill_on_drop: false }`
[INFO] [stdout] 94815cb707d48d56b5bc7c12d205c08dcc3cb1bd8488c9f83409512b46b32218