[INFO] fetching crate json-ld 0.2.0-alpha...
[INFO] testing json-ld-0.2.0-alpha against 1.54.0 for beta-1.55-1
[INFO] extracting crate json-ld 0.2.0-alpha into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate json-ld 0.2.0-alpha on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", 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-3/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" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", 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] 76c57a08bb6f806d22d858218aab1e310cc887e2a65d126ee365cf25b184d5b5
[INFO] running `Command { std: "docker" "start" "-a" "76c57a08bb6f806d22d858218aab1e310cc887e2a65d126ee365cf25b184d5b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "76c57a08bb6f806d22d858218aab1e310cc887e2a65d126ee365cf25b184d5b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "76c57a08bb6f806d22d858218aab1e310cc887e2a65d126ee365cf25b184d5b5", kill_on_drop: false }`
[INFO] [stdout] 76c57a08bb6f806d22d858218aab1e310cc887e2a65d126ee365cf25b184d5b5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1f5d7c69d5c9c97dbc1a264a3056239bf3215c90d5af02bae725a395752e7a87
[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" "1f5d7c69d5c9c97dbc1a264a3056239bf3215c90d5af02bae725a395752e7a87", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.16
[INFO] [stderr]    Compiling futures-sink v0.3.4
[INFO] [stderr]    Compiling futures-io v0.3.4
[INFO] [stderr]    Compiling pct-str v1.0.2
[INFO] [stderr]    Compiling json v0.12.3
[INFO] [stderr]    Compiling mown v0.2.0
[INFO] [stderr]    Compiling futures-channel v0.3.4
[INFO] [stderr]    Compiling iref v1.1.5
[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 stable 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 stable 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" "1f5d7c69d5c9c97dbc1a264a3056239bf3215c90d5af02bae725a395752e7a87", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1f5d7c69d5c9c97dbc1a264a3056239bf3215c90d5af02bae725a395752e7a87", kill_on_drop: false }`
[INFO] [stdout] 1f5d7c69d5c9c97dbc1a264a3056239bf3215c90d5af02bae725a395752e7a87
