[INFO] updating cached repository https://github.com/kyle-coblentz/grap
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] d41d5bb6a29f87de22adf4393559e91ecbc0fd47
[INFO] checking kyle-coblentz/grap against try#1a608893c03d7722effeb0058e82770bd36b4b3c for pr-66504-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkyle-coblentz%2Fgrap" "/workspace/builds/worker-8/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/kyle-coblentz/grap on toolchain 1a608893c03d7722effeb0058e82770bd36b4b3c
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1a608893c03d7722effeb0058e82770bd36b4b3c" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/kyle-coblentz/grap
[INFO] finished tweaking git repo https://github.com/kyle-coblentz/grap
[INFO] tweaked toml for git repo https://github.com/kyle-coblentz/grap written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/kyle-coblentz/grap already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1a608893c03d7722effeb0058e82770bd36b4b3c" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1a608893c03d7722effeb0058e82770bd36b4b3c" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 3c8636aabbec35df9d0060d198bceb935959f9f107a7bb4cecaaf19e875318de
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `"docker" "start" "-a" "3c8636aabbec35df9d0060d198bceb935959f9f107a7bb4cecaaf19e875318de"`
[INFO] [stderr]     Checking grap v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0277]: cannot add `&mut std::string::String` to `std::string::String`
[INFO] [stderr]   --> src/main.rs:87:59
[INFO] [stderr]    |
[INFO] [stderr] 87 |            .expect((String::from("Could not open file: ") + &mut file).as_str())
[INFO] [stderr]    |                                                           ^ no implementation for `std::string::String + &mut std::string::String`
[INFO] [stderr]    |
[INFO] [stderr]    = help: the trait `std::ops::Add<&mut std::string::String>` is not implemented for `std::string::String`
[INFO] [stderr] 
[INFO] [stderr] error[E0277]: cannot add `&mut std::string::String` to `std::string::String`
[INFO] [stderr]   --> src/main.rs:87:59
[INFO] [stderr]    |
[INFO] [stderr] 87 |            .expect((String::from("Could not open file: ") + &mut file).as_str())
[INFO] [stderr]    |                                                           ^ no implementation for `std::string::String + &mut std::string::String`
[INFO] [stderr]    |
[INFO] [stderr]    = help: the trait `std::ops::Add<&mut std::string::String>` is not implemented for `std::string::String`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0277`.
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0277`.
[INFO] [stderr] error: could not compile `grap`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `grap`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "3c8636aabbec35df9d0060d198bceb935959f9f107a7bb4cecaaf19e875318de"`
[INFO] running `"docker" "rm" "-f" "3c8636aabbec35df9d0060d198bceb935959f9f107a7bb4cecaaf19e875318de"`
[INFO] [stdout] 3c8636aabbec35df9d0060d198bceb935959f9f107a7bb4cecaaf19e875318de