[INFO] fetching crate json-ld 0.2.0-alpha...
[INFO] testing json-ld-0.2.0-alpha against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate json-ld 0.2.0-alpha into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate json-ld 0.2.0-alpha on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate json-ld 0.2.0-alpha
[INFO] removed 0 missing examples
[INFO] finished tweaking crates.io crate json-ld 0.2.0-alpha
[INFO] tweaked toml for crates.io crate json-ld 0.2.0-alpha written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate crates.io crate json-ld 0.2.0-alpha already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded schannel v0.1.17
[INFO] [stderr]   Downloaded proc-macro-hack v0.5.12
[INFO] [stderr]   Downloaded hyper v0.13.3
[INFO] [stderr]   Downloaded iref v1.1.5
[INFO] [stderr]   Downloaded pct-str v1.0.2
[INFO] [stderr]   Downloaded static-iref v1.0.0
[INFO] [stderr]   Downloaded mown v0.2.0
[INFO] [stderr]   Downloaded json v0.12.3
[INFO] [stderr]   Downloaded iref-enum v1.0.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8b9be213820e33e0d8ceba026b748878a7ab83c30613e040bf83cf2cfc31938e
[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" "8b9be213820e33e0d8ceba026b748878a7ab83c30613e040bf83cf2cfc31938e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8b9be213820e33e0d8ceba026b748878a7ab83c30613e040bf83cf2cfc31938e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8b9be213820e33e0d8ceba026b748878a7ab83c30613e040bf83cf2cfc31938e", kill_on_drop: false }`
[INFO] [stdout] 8b9be213820e33e0d8ceba026b748878a7ab83c30613e040bf83cf2cfc31938e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "build" "--frozen" "--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] 6e5c933aa073a7e8e14e3fd9155c9b226ab4b4942f7df6b4551bf086d3698496
[INFO] running `Command { std: "docker" "start" "-a" "6e5c933aa073a7e8e14e3fd9155c9b226ab4b4942f7df6b4551bf086d3698496", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.9
[INFO] [stderr]    Compiling syn v1.0.16
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling proc-macro-nested v0.1.4
[INFO] [stderr]    Compiling futures-sink v0.3.4
[INFO] [stderr]    Compiling futures-core v0.3.4
[INFO] [stderr]    Compiling futures-task v0.3.4
[INFO] [stderr]    Compiling pin-utils v0.1.0-alpha.4
[INFO] [stderr]    Compiling futures-io v0.3.4
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling pct-str v1.0.2
[INFO] [stderr]    Compiling smallvec v1.2.0
[INFO] [stderr]    Compiling mown v0.2.0
[INFO] [stderr]    Compiling json v0.12.3
[INFO] [stderr]    Compiling futures-channel v0.3.4
[INFO] [stderr]    Compiling iref v1.1.5
[INFO] [stderr]    Compiling quote v1.0.3
[INFO] [stderr]    Compiling proc-macro-hack v0.5.12
[INFO] [stderr]    Compiling futures-macro v0.3.4
[INFO] [stderr]    Compiling futures-util v0.3.4
[INFO] [stderr]    Compiling futures-executor v0.3.4
[INFO] [stderr]    Compiling futures v0.3.4
[INFO] [stderr]    Compiling json-ld v0.2.0-alpha (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(str_strip)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(arbitrary_self_types)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `json-ld`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "6e5c933aa073a7e8e14e3fd9155c9b226ab4b4942f7df6b4551bf086d3698496", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6e5c933aa073a7e8e14e3fd9155c9b226ab4b4942f7df6b4551bf086d3698496", kill_on_drop: false }`
[INFO] [stdout] 6e5c933aa073a7e8e14e3fd9155c9b226ab4b4942f7df6b4551bf086d3698496