[INFO] fetching crate pgc 0.3.0...
[INFO] testing pgc-0.3.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate pgc 0.3.0 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate pgc 0.3.0 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 pgc 0.3.0
[INFO] finished tweaking crates.io crate pgc 0.3.0
[INFO] tweaked toml for crates.io crate pgc 0.3.0 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate crates.io crate pgc 0.3.0 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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] eea99f5795c9c4802f88eba653fc25e3b1d0a28cea0f5ae93e3867f6bb4e89ee
[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" "eea99f5795c9c4802f88eba653fc25e3b1d0a28cea0f5ae93e3867f6bb4e89ee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "eea99f5795c9c4802f88eba653fc25e3b1d0a28cea0f5ae93e3867f6bb4e89ee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "eea99f5795c9c4802f88eba653fc25e3b1d0a28cea0f5ae93e3867f6bb4e89ee", kill_on_drop: false }`
[INFO] [stdout] eea99f5795c9c4802f88eba653fc25e3b1d0a28cea0f5ae93e3867f6bb4e89ee
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 733c7e604e875b81074bec3d2ec939385c58784c220ff0d5e7857e82a657c221
[INFO] running `Command { std: "docker" "start" "-a" "733c7e604e875b81074bec3d2ec939385c58784c220ff0d5e7857e82a657c221", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]    Compiling getrandom v0.1.12
[INFO] [stderr]    Compiling cc v1.0.45
[INFO] [stderr]    Compiling scopeguard v1.0.0
[INFO] [stderr]    Compiling arrayvec v0.4.11
[INFO] [stderr]    Compiling ppv-lite86 v0.2.5
[INFO] [stderr]    Compiling nodrop v0.1.13
[INFO] [stderr]    Compiling smallvec v0.6.10
[INFO] [stderr]    Compiling memoffset v0.5.1
[INFO] [stderr]    Compiling lock_api v0.3.1
[INFO] [stderr]    Compiling c2-chacha v0.2.2
[INFO] [stderr]    Compiling cmake v0.1.42
[INFO] [stderr]    Compiling crossbeam-epoch v0.7.2
[INFO] [stderr]    Compiling libmimalloc-sys v0.1.6
[INFO] [stderr]    Compiling parking_lot_core v0.6.2
[INFO] [stderr]    Compiling num_cpus v1.10.1
[INFO] [stderr]    Compiling time v0.1.42
[INFO] [stderr]    Compiling crossbeam-deque v0.7.1
[INFO] [stderr]    Compiling threadpool v1.7.1
[INFO] [stderr]    Compiling parking_lot v0.9.0
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.1
[INFO] [stderr]    Compiling rand v0.7.2
[INFO] [stderr]    Compiling mimalloc v0.1.9
[INFO] [stderr]    Compiling pgc v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:8:1
[INFO] [stdout]   |
[INFO] [stdout] 8 | #![feature(coerce_unsized)]
[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:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(unsize)]
[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 `pgc`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "733c7e604e875b81074bec3d2ec939385c58784c220ff0d5e7857e82a657c221", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "733c7e604e875b81074bec3d2ec939385c58784c220ff0d5e7857e82a657c221", kill_on_drop: false }`
[INFO] [stdout] 733c7e604e875b81074bec3d2ec939385c58784c220ff0d5e7857e82a657c221