[INFO] cloning repository https://github.com/mknet/rust-mockall-playground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mknet/rust-mockall-playground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmknet%2Frust-mockall-playground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmknet%2Frust-mockall-playground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 492143413c058e53d566c49b0651d8160782ad6c
[INFO] checking mknet/rust-mockall-playground against 1.55.0 for beta-1.56-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmknet%2Frust-mockall-playground" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mknet/rust-mockall-playground on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/mknet/rust-mockall-playground
[INFO] finished tweaking git repo https://github.com/mknet/rust-mockall-playground
[INFO] tweaked toml for git repo https://github.com/mknet/rust-mockall-playground written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/mknet/rust-mockall-playground already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded downcast v0.10.0
[INFO] [stderr]   Downloaded mockall_derive v0.9.0
[INFO] [stderr]   Downloaded float-cmp v0.6.0
[INFO] [stderr]   Downloaded mockall v0.9.0
[INFO] [stderr]   Downloaded predicates v1.0.4
[INFO] [stderr]   Downloaded predicates-core v1.0.0
[INFO] [stderr]   Downloaded predicates-tree v1.0.0
[INFO] [stderr]   Downloaded fragile v1.0.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] af6e0f9f0674f0c60b3587c54416e8237f742359e1cbf97888d5e4c029a3a24c
[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" "af6e0f9f0674f0c60b3587c54416e8237f742359e1cbf97888d5e4c029a3a24c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "af6e0f9f0674f0c60b3587c54416e8237f742359e1cbf97888d5e4c029a3a24c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "af6e0f9f0674f0c60b3587c54416e8237f742359e1cbf97888d5e4c029a3a24c", kill_on_drop: false }`
[INFO] [stdout] af6e0f9f0674f0c60b3587c54416e8237f742359e1cbf97888d5e4c029a3a24c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "check" "--frozen" "--all" "--all-targets" "--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] 65908cf9583f92315b5f8e207fdfec20bc27d7a78d6eab72b32356718ea1dce7
[INFO] running `Command { std: "docker" "start" "-a" "65908cf9583f92315b5f8e207fdfec20bc27d7a78d6eab72b32356718ea1dce7", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.33
[INFO] [stderr]     Checking fragile v1.0.0
[INFO] [stderr]     Checking downcast v0.10.0
[INFO] [stderr]     Checking float-cmp v0.6.0
[INFO] [stderr]     Checking predicates v1.0.4
[INFO] [stderr]    Compiling mockall_derive v0.9.0
[INFO] [stderr]     Checking mockall v0.9.0
[INFO] [stderr]     Checking mockall-playground v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:19
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![cfg_attr(test, feature(proc_macro_hygiene))]
[INFO] [stdout]   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `mockall-playground` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "65908cf9583f92315b5f8e207fdfec20bc27d7a78d6eab72b32356718ea1dce7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "65908cf9583f92315b5f8e207fdfec20bc27d7a78d6eab72b32356718ea1dce7", kill_on_drop: false }`
[INFO] [stdout] 65908cf9583f92315b5f8e207fdfec20bc27d7a78d6eab72b32356718ea1dce7
