[INFO] fetching crate mech-program 0.0.5...
[INFO] checking mech-program-0.0.5 against beta for pr-78714
[INFO] extracting crate mech-program 0.0.5 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate mech-program 0.0.5 on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mech-program 0.0.5
[INFO] finished tweaking crates.io crate mech-program 0.0.5
[INFO] tweaked toml for crates.io crate mech-program 0.0.5 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate crates.io crate mech-program 0.0.5 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "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] 1077d96facb671d7586a9fdb7f29a81486cb0acd716eee83925decec3b1beb1b
[INFO] running `Command { std: "docker" "start" "-a" "1077d96facb671d7586a9fdb7f29a81486cb0acd716eee83925decec3b1beb1b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1077d96facb671d7586a9fdb7f29a81486cb0acd716eee83925decec3b1beb1b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1077d96facb671d7586a9fdb7f29a81486cb0acd716eee83925decec3b1beb1b", kill_on_drop: false }`
[INFO] [stdout] 1077d96facb671d7586a9fdb7f29a81486cb0acd716eee83925decec3b1beb1b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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=forbid" "-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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3491f196782528624c05dcf5729a9ff2e4dbbed1171b9890dd0d465b7b3653a6
[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" "3491f196782528624c05dcf5729a9ff2e4dbbed1171b9890dd0d465b7b3653a6", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.69
[INFO] [stderr]     Checking futures v0.1.29
[INFO] [stderr]    Compiling cc v1.0.52
[INFO] [stderr]    Compiling syn v1.0.18
[INFO] [stderr]     Checking smallvec v1.4.0
[INFO] [stderr]     Checking itoa v0.4.5
[INFO] [stderr]    Compiling serde v1.0.106
[INFO] [stderr]     Checking ppv-lite86 v0.2.6
[INFO] [stderr]     Checking regex-syntax v0.6.17
[INFO] [stderr]    Compiling crc32fast v1.2.0
[INFO] [stderr]    Compiling encoding_rs v0.8.22
[INFO] [stderr]     Checking bytes v0.5.4
[INFO] [stderr]    Compiling libloading v0.6.2
[INFO] [stderr]     Checking dtoa v0.4.5
[INFO] [stderr]     Checking base64 v0.11.0
[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 indexmap v1.3.2
[INFO] [stderr]    Compiling error-chain v0.12.2
[INFO] [stderr]     Checking try_from v0.3.2
[INFO] [stderr]     Checking miniz_oxide v0.3.6
[INFO] [stderr]     Checking log v0.4.8
[INFO] [stderr]     Checking unicode-normalization v0.1.12
[INFO] [stderr]    Compiling quote v1.0.4
[INFO] [stderr]     Checking hashbrown v0.7.2
[INFO] [stderr]     Checking input_buffer v0.3.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/hashbrown-0.7.2/src/lib.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 | /     feature(
[INFO] [stdout] 16 | |         alloc_layout_extra,
[INFO] [stdout] 17 | |         allocator_api,
[INFO] [stdout] 18 | |         ptr_offset_from,
[INFO] [stdout] ...  |
[INFO] [stdout] 22 | |         specialization,
[INFO] [stdout] 23 | |     )
[INFO] [stdout]    | |_____^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking http v0.2.1
[INFO] [stderr]    Compiling mime_guess v2.0.3
[INFO] [stderr]     Checking lexical-core v0.6.7
[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 `hashbrown`
[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" "3491f196782528624c05dcf5729a9ff2e4dbbed1171b9890dd0d465b7b3653a6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3491f196782528624c05dcf5729a9ff2e4dbbed1171b9890dd0d465b7b3653a6", kill_on_drop: false }`
[INFO] [stdout] 3491f196782528624c05dcf5729a9ff2e4dbbed1171b9890dd0d465b7b3653a6