[INFO] updating cached repository https://github.com/phansch/rust-worksheets
[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] 21360376228c886a324bbd617b37771c2d7f812d
[INFO] checking phansch/rust-worksheets against try#1a608893c03d7722effeb0058e82770bd36b4b3c for pr-66504-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fphansch%2Frust-worksheets" "/workspace/builds/worker-5/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/phansch/rust-worksheets 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/phansch/rust-worksheets
[INFO] finished tweaking git repo https://github.com/phansch/rust-worksheets
[INFO] tweaked toml for git repo https://github.com/phansch/rust-worksheets written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/phansch/rust-worksheets 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-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 3cae78b75cfe22ffa58c9759722c6ca8ebfc7743383570fc150ec308ca2fcdfd
[INFO] running `"docker" "start" "-a" "3cae78b75cfe22ffa58c9759722c6ca8ebfc7743383570fc150ec308ca2fcdfd"`
[INFO] [stderr]    Compiling rustc-demangle v0.1.8
[INFO] [stderr]    Compiling brotli-sys v0.3.2
[INFO] [stderr]    Compiling actix_derive v0.2.0
[INFO] [stderr]    Compiling actix-web v0.6.14
[INFO] [stderr]    Compiling rand v0.3.22
[INFO] [stderr]    Compiling pulldown-cmark v0.1.2
[INFO] [stderr]     Checking tokio-io v0.1.7
[INFO] [stderr]     Checking parking_lot v0.5.5
[INFO] [stderr]    Compiling backtrace-sys v0.1.23
[INFO] [stderr]     Checking mio-uds v0.6.6
[INFO] [stderr]    Compiling serde_json v1.0.22
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling crossbeam-deque v0.2.0
[INFO] [stderr] error[E0277]: cannot add `&std::borrow::Cow<'_, str>` to `std::string::String`
[INFO] [stderr]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/pulldown-cmark-0.1.2/src/utils.rs:51:30
[INFO] [stderr]    |
[INFO] [stderr] 51 |         Owned(a.into_owned() + &b)
[INFO] [stderr]    |                              ^ no implementation for `std::string::String + &std::borrow::Cow<'_, str>`
[INFO] [stderr]    |
[INFO] [stderr]    = help: the trait `std::ops::Add<&std::borrow::Cow<'_, str>>` 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: could not compile `pulldown-cmark`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "3cae78b75cfe22ffa58c9759722c6ca8ebfc7743383570fc150ec308ca2fcdfd"`
[INFO] running `"docker" "rm" "-f" "3cae78b75cfe22ffa58c9759722c6ca8ebfc7743383570fc150ec308ca2fcdfd"`
[INFO] [stdout] 3cae78b75cfe22ffa58c9759722c6ca8ebfc7743383570fc150ec308ca2fcdfd