[INFO] fetching crate boa_string 0.21.0...
[INFO] checking boa_string-0.21.0 against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] extracting crate boa_string 0.21.0 into /workspace/builds/worker-0-tc2/source
[INFO] started tweaking crates.io crate boa_string 0.21.0
[INFO] finished tweaking crates.io crate boa_string 0.21.0
[INFO] tweaked toml for crates.io crate boa_string 0.21.0 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate boa_string 0.21.0 on toolchain 4f260f0f20b3133d20cfb50353c0221943af5796
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate boa_string 0.21.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 639806c97aa344e8876b42637ab699680afd1e5dfc8be3bc63e61d04cc0e9f18
[INFO] running `Command { std: "docker" "start" "-a" "639806c97aa344e8876b42637ab699680afd1e5dfc8be3bc63e61d04cc0e9f18", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "639806c97aa344e8876b42637ab699680afd1e5dfc8be3bc63e61d04cc0e9f18", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "639806c97aa344e8876b42637ab699680afd1e5dfc8be3bc63e61d04cc0e9f18", kill_on_drop: false }`
[INFO] [stdout] 639806c97aa344e8876b42637ab699680afd1e5dfc8be3bc63e61d04cc0e9f18
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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 -Dunmustuse_in_always_ok" "-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7207998c300b9de9776bc07cd0496c1ae9e3e766bcd635c26eefe45d53f9bb0e
[INFO] running `Command { std: "docker" "start" "-a" "7207998c300b9de9776bc07cd0496c1ae9e3e766bcd635c26eefe45d53f9bb0e", kill_on_drop: false }`
[INFO] [stderr]     Checking fast-float2 v0.2.3
[INFO] [stderr]     Checking ryu-js v1.0.2
[INFO] [stderr]     Checking boa_string v0.21.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: this type will no longer be must used: Result<JsString, Infallible>
[INFO] [stdout]     --> src/lib.rs:1067:53
[INFO] [stdout]      |
[INFO] [stdout] 1067 |       fn from_str(s: &str) -> Result<Self, Self::Err> {
[INFO] [stdout]      |  _____________________________________________________^
[INFO] [stdout] 1068 | |         Ok(Self::from(s))
[INFO] [stdout] 1069 | |     }
[INFO] [stdout]      | |_____^
[INFO] [stdout]      |
[INFO] [stdout]      = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<JsString, Infallible>
[INFO] [stdout]     --> src/lib.rs:1068:9
[INFO] [stdout]      |
[INFO] [stdout] 1068 |         Ok(Self::from(s))
[INFO] [stdout]      |         ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `boa_string` (lib test) due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: this type will no longer be must used: Result<JsString, Infallible>
[INFO] [stdout]     --> src/lib.rs:1067:53
[INFO] [stdout]      |
[INFO] [stdout] 1067 |       fn from_str(s: &str) -> Result<Self, Self::Err> {
[INFO] [stdout]      |  _____________________________________________________^
[INFO] [stdout] 1068 | |         Ok(Self::from(s))
[INFO] [stdout] 1069 | |     }
[INFO] [stdout]      | |_____^
[INFO] [stdout]      |
[INFO] [stdout]      = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<JsString, Infallible>
[INFO] [stdout]     --> src/lib.rs:1068:9
[INFO] [stdout]      |
[INFO] [stdout] 1068 |         Ok(Self::from(s))
[INFO] [stdout]      |         ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `boa_string` (lib) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "7207998c300b9de9776bc07cd0496c1ae9e3e766bcd635c26eefe45d53f9bb0e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7207998c300b9de9776bc07cd0496c1ae9e3e766bcd635c26eefe45d53f9bb0e", kill_on_drop: false }`
[INFO] [stdout] 7207998c300b9de9776bc07cd0496c1ae9e3e766bcd635c26eefe45d53f9bb0e