[INFO] fetching crate rems 0.0.2...
[INFO] testing rems-0.0.2 against 1.49.0 for beta-1.50-1
[INFO] extracting crate rems 0.0.2 into /workspace/builds/worker-11/source
[INFO] validating manifest of crates.io crate rems 0.0.2 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rems 0.0.2
[INFO] finished tweaking crates.io crate rems 0.0.2
[INFO] tweaked toml for crates.io crate rems 0.0.2 written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate crates.io crate rems 0.0.2 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 87aae1cee7e8d802a9db8dfca68ffc6c24c94ba22d4f7cff14a5c4ca52fd584b
[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" "87aae1cee7e8d802a9db8dfca68ffc6c24c94ba22d4f7cff14a5c4ca52fd584b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "87aae1cee7e8d802a9db8dfca68ffc6c24c94ba22d4f7cff14a5c4ca52fd584b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "87aae1cee7e8d802a9db8dfca68ffc6c24c94ba22d4f7cff14a5c4ca52fd584b", kill_on_drop: false }`
[INFO] [stdout] 87aae1cee7e8d802a9db8dfca68ffc6c24c94ba22d4f7cff14a5c4ca52fd584b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 53e81efe1e0bcc77f750a9056d996178589075590006a97efa43057a9a22f98d
[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" "53e81efe1e0bcc77f750a9056d996178589075590006a97efa43057a9a22f98d", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.9
[INFO] [stderr]    Compiling syn v1.0.17
[INFO] [stderr]    Compiling libc v0.2.74
[INFO] [stderr]    Compiling serde v1.0.105
[INFO] [stderr]    Compiling ryu v1.0.3
[INFO] [stderr]    Compiling proc-macro-hack v0.5.14
[INFO] [stderr]    Compiling smallvec v1.4.0
[INFO] [stderr]    Compiling unindent v0.1.5
[INFO] [stderr]    Compiling regex-syntax v0.6.17
[INFO] [stderr]    Compiling instant v0.1.6
[INFO] [stderr]    Compiling rayon-core v1.7.0
[INFO] [stderr]    Compiling pyo3 v0.11.1
[INFO] [stderr]    Compiling dtoa v0.4.5
[INFO] [stderr]    Compiling hex v0.3.2
[INFO] [stderr]    Compiling md5 v0.6.1
[INFO] [stderr]    Compiling num-traits v0.2.11
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling memoffset v0.5.4
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling lock_api v0.3.4
[INFO] [stderr]    Compiling num-integer v0.1.42
[INFO] [stderr]    Compiling lock_api v0.4.1
[INFO] [stderr]    Compiling yaml-rust v0.4.3
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/lock_api-0.3.4/src/lib.rs:91:34
[INFO] [stdout]    |
[INFO] [stdout] 91 | #![cfg_attr(feature = "nightly", feature(const_fn))]
[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 `lock_api`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "53e81efe1e0bcc77f750a9056d996178589075590006a97efa43057a9a22f98d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "53e81efe1e0bcc77f750a9056d996178589075590006a97efa43057a9a22f98d", kill_on_drop: false }`
[INFO] [stdout] 53e81efe1e0bcc77f750a9056d996178589075590006a97efa43057a9a22f98d