[INFO] cloning repository https://github.com/metempsychosia/isola
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/metempsychosia/isola" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmetempsychosia%2Fisola", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmetempsychosia%2Fisola'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 31233ab9a74cf0f48f1f8a259acd0bb31b443bc8
[INFO] testing metempsychosia/isola against master#1f7f8ea0721a3b1eb73e6c6d25cccb371434b320 for pr-154065-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmetempsychosia%2Fisola" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/metempsychosia/isola
[INFO] finished tweaking git repo https://github.com/metempsychosia/isola
[INFO] tweaked toml for git repo https://github.com/metempsychosia/isola written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/metempsychosia/isola on toolchain 1f7f8ea0721a3b1eb73e6c6d25cccb371434b320
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1f7f8ea0721a3b1eb73e6c6d25cccb371434b320" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/metempsychosia/isola 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" "+1f7f8ea0721a3b1eb73e6c6d25cccb371434b320" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1f7f8ea0721a3b1eb73e6c6d25cccb371434b320" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4bed0a37c6fbe30d1924d4d63b45cf378e3e11712bb2b97a06f866d05c38997c
[INFO] running `Command { std: "docker" "start" "-a" "4bed0a37c6fbe30d1924d4d63b45cf378e3e11712bb2b97a06f866d05c38997c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4bed0a37c6fbe30d1924d4d63b45cf378e3e11712bb2b97a06f866d05c38997c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4bed0a37c6fbe30d1924d4d63b45cf378e3e11712bb2b97a06f866d05c38997c", kill_on_drop: false }`
[INFO] [stdout] 4bed0a37c6fbe30d1924d4d63b45cf378e3e11712bb2b97a06f866d05c38997c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1f7f8ea0721a3b1eb73e6c6d25cccb371434b320" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b74c93d4b6dcbe2051250f546d3e2f161e0ff0d035151dad7478a8f2df5d614d
[INFO] running `Command { std: "docker" "start" "-a" "b74c93d4b6dcbe2051250f546d3e2f161e0ff0d035151dad7478a8f2df5d614d", kill_on_drop: false }`
[INFO] [stderr]    Compiling isola v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::path`
[INFO] [stdout]  --> src/io.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::path;
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]   --> src/io.rs:11:24
[INFO] [stdout]    |
[INFO] [stdout]  6 | pub fn read(filename: &str) -> Result<String, Box<dyn Error>> {
[INFO] [stdout]    |                                ------------------------------ expected `Result<String, Box<(dyn std::error::Error + 'static)>>` because of return type
[INFO] [stdout] ...
[INFO] [stdout] 11 |                 return fs::read_to_string(filename);
[INFO] [stdout]    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Result<String, Box<dyn Error>>`, found `Result<String, Error>`
[INFO] [stdout]    |
[INFO] [stdout]    = note: expected enum `Result<_, Box<(dyn std::error::Error + 'static)>>`
[INFO] [stdout]               found enum `Result<_, std::io::Error>`
[INFO] [stdout] help: use `?` to coerce and return an appropriate `Err`, and wrap the resulting value in `Ok` so the expression remains of type `Result`
[INFO] [stdout]    |
[INFO] [stdout] 11 |                 return Ok(fs::read_to_string(filename)?);
[INFO] [stdout]    |                        +++                            ++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0308`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `isola` (bin "isola") due to 1 previous error; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "b74c93d4b6dcbe2051250f546d3e2f161e0ff0d035151dad7478a8f2df5d614d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b74c93d4b6dcbe2051250f546d3e2f161e0ff0d035151dad7478a8f2df5d614d", kill_on_drop: false }`
[INFO] [stdout] b74c93d4b6dcbe2051250f546d3e2f161e0ff0d035151dad7478a8f2df5d614d