[INFO] fetching crate slam-cv 0.1.3...
[INFO] testing slam-cv-0.1.3 against 1.49.0 for beta-1.50-1
[INFO] extracting crate slam-cv 0.1.3 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate slam-cv 0.1.3 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 slam-cv 0.1.3
[INFO] finished tweaking crates.io crate slam-cv 0.1.3
[INFO] tweaked toml for crates.io crate slam-cv 0.1.3 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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-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" "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] d420c3701f54d6315fcd107291126488e042ea9d6c17476eb3f4f61cf2732ebb
[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" "d420c3701f54d6315fcd107291126488e042ea9d6c17476eb3f4f61cf2732ebb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d420c3701f54d6315fcd107291126488e042ea9d6c17476eb3f4f61cf2732ebb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d420c3701f54d6315fcd107291126488e042ea9d6c17476eb3f4f61cf2732ebb", kill_on_drop: false }`
[INFO] [stdout] d420c3701f54d6315fcd107291126488e042ea9d6c17476eb3f4f61cf2732ebb
[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" "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] 4a0e17eec16fbfc7a46418c7c24c3ba8ddbd10f8e029ff9b620c686eb96e8222
[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" "4a0e17eec16fbfc7a46418c7c24c3ba8ddbd10f8e029ff9b620c686eb96e8222", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.57
[INFO] [stderr]    Compiling sample-consensus v0.2.0
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling rand_distr v0.2.2
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling approx v0.3.2
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling num-rational v0.3.2
[INFO] [stderr]    Compiling simba v0.1.5
[INFO] [stderr]    Compiling image v0.23.12
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling derive_more v0.99.11
[INFO] [stderr]    Compiling nalgebra v0.21.1
[INFO] [stderr]    Compiling num v0.2.1
[INFO] [stderr]    Compiling cv-core v0.10.0
[INFO] [stderr]    Compiling slam-cv v0.1.3 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(associated_type_defaults)]
[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 `slam-cv`
[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" "4a0e17eec16fbfc7a46418c7c24c3ba8ddbd10f8e029ff9b620c686eb96e8222", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4a0e17eec16fbfc7a46418c7c24c3ba8ddbd10f8e029ff9b620c686eb96e8222", kill_on_drop: false }`
[INFO] [stdout] 4a0e17eec16fbfc7a46418c7c24c3ba8ddbd10f8e029ff9b620c686eb96e8222