[INFO] fetching crate mech 0.0.5...
[INFO] testing mech-0.0.5 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate mech 0.0.5 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate mech 0.0.5 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 mech 0.0.5
[INFO] finished tweaking crates.io crate mech 0.0.5
[INFO] tweaked toml for crates.io crate mech 0.0.5 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate crates.io crate mech 0.0.5 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 futures-macro v0.3.4
[INFO] [stderr]   Downloaded actix-web-actors v2.0.0
[INFO] [stderr]   Downloaded actix-http v1.0.1
[INFO] [stderr]   Downloaded trust-dns-resolver v0.18.0-alpha.2
[INFO] [stderr]   Downloaded wasm-bindgen-futures v0.4.12
[INFO] [stderr]   Downloaded pin-project v0.4.10
[INFO] [stderr]   Downloaded js-sys v0.3.39
[INFO] [stderr]   Downloaded actix-connect v1.0.2
[INFO] [stderr]   Downloaded lexical-core v0.6.2
[INFO] [stderr]   Downloaded threadpool v1.8.0
[INFO] [stderr]   Downloaded futures v0.3.4
[INFO] [stderr]   Downloaded trust-dns-proto v0.18.0-alpha.2
[INFO] [stderr]   Downloaded ring v0.16.13
[INFO] [stderr]   Downloaded actix-session v0.3.0
[INFO] [stderr]   Downloaded async-trait v0.1.30
[INFO] [stderr]   Downloaded mech-program v0.0.5
[INFO] [stderr]   Downloaded actix v0.9.0
[INFO] [stderr]   Downloaded web-sys v0.3.39
[INFO] [stderr]   Downloaded awc v1.0.1
[INFO] [stderr]   Downloaded actix-files v0.2.1
[INFO] [stderr]   Downloaded actix-tls v1.0.0
[INFO] [stderr]   Downloaded pin-project-internal v0.4.10
[INFO] [stderr]   Downloaded actix-web v2.0.0
[INFO] [stderr]   Downloaded futures-executor v0.3.4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "+beta-2021-01-01" "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] 3b31e16c027ab60fbef39533375154dc2d95bc053880f082b475df8f88652b2c
[INFO] running `Command { std: "docker" "start" "-a" "3b31e16c027ab60fbef39533375154dc2d95bc053880f082b475df8f88652b2c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3b31e16c027ab60fbef39533375154dc2d95bc053880f082b475df8f88652b2c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3b31e16c027ab60fbef39533375154dc2d95bc053880f082b475df8f88652b2c", kill_on_drop: false }`
[INFO] [stdout] 3b31e16c027ab60fbef39533375154dc2d95bc053880f082b475df8f88652b2c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "+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] d86c6e6923e13036977a91527b9bbe514332ee67114372488b7737cf69202037
[INFO] running `Command { std: "docker" "start" "-a" "d86c6e6923e13036977a91527b9bbe514332ee67114372488b7737cf69202037", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.69
[INFO] [stderr]    Compiling proc-macro2 v1.0.12
[INFO] [stderr]    Compiling syn v1.0.18
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling cc v1.0.52
[INFO] [stderr]    Compiling smallvec v1.4.0
[INFO] [stderr]    Compiling bytes v0.5.4
[INFO] [stderr]    Compiling futures-core v0.3.4
[INFO] [stderr]    Compiling futures-sink v0.3.4
[INFO] [stderr]    Compiling arc-swap v0.4.6
[INFO] [stderr]    Compiling proc-macro-nested v0.1.4
[INFO] [stderr]    Compiling proc-macro-hack v0.5.15
[INFO] [stderr]    Compiling pin-project-lite v0.1.4
[INFO] [stderr]    Compiling futures-task v0.3.4
[INFO] [stderr]    Compiling futures-io v0.3.4
[INFO] [stderr]    Compiling serde v1.0.106
[INFO] [stderr]    Compiling ryu v1.0.4
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling pkg-config v0.3.17
[INFO] [stderr]    Compiling copyless v0.1.4
[INFO] [stderr]    Compiling regex-syntax v0.6.17
[INFO] [stderr]    Compiling crc32fast v1.2.0
[INFO] [stderr]    Compiling encoding_rs v0.8.22
[INFO] [stderr]    Compiling adler32 v1.0.4
[INFO] [stderr]    Compiling match_cfg v0.1.0
[INFO] [stderr]    Compiling foreign-types-shared v0.1.1
[INFO] [stderr]    Compiling linked-hash-map v0.5.3
[INFO] [stderr]    Compiling openssl v0.10.29
[INFO] [stderr]    Compiling native-tls v0.2.4
[INFO] [stderr]    Compiling once_cell v1.3.1
[INFO] [stderr]    Compiling openssl-probe v0.1.2
[INFO] [stderr]    Compiling sha1 v0.6.0
[INFO] [stderr]    Compiling language-tags v0.2.2
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]    Compiling ahash v0.3.4
[INFO] [stderr]    Compiling nodrop v0.1.14
[INFO] [stderr]    Compiling static_assertions v0.3.4
[INFO] [stderr]    Compiling libloading v0.6.2
[INFO] [stderr]    Compiling v_htmlescape v0.4.5
[INFO] [stderr]    Compiling lazycell v1.2.1
[INFO] [stderr]    Compiling num-traits v0.2.11
[INFO] [stderr]    Compiling num-integer v0.1.42
[INFO] [stderr]    Compiling hashbrown v0.7.2
[INFO] [stderr]    Compiling try_from v0.3.2
[INFO] [stderr]    Compiling futures-channel v0.3.4
[INFO] [stderr]    Compiling unicase v2.6.0
[INFO] [stderr]    Compiling error-chain v0.12.2
[INFO] [stderr]    Compiling nom v5.1.1
[INFO] [stderr]    Compiling unicode-normalization v0.1.12
[INFO] [stderr]    Compiling http v0.2.1
[INFO] [stderr]    Compiling bytestring v0.1.5
[INFO] [stderr]    Compiling input_buffer v0.3.1
[INFO] [stderr]    Compiling miniz_oxide v0.3.6
[INFO] [stderr]    Compiling foreign-types v0.3.2
[INFO] [stderr]    Compiling nom v4.2.3
[INFO] [stderr]    Compiling lru-cache v0.1.2
[INFO] [stderr]    Compiling fxhash v0.2.1
[INFO] [stderr]    Compiling base64 v0.10.1
[INFO] [stderr]    Compiling lexical-core v0.6.2
[INFO] [stderr]    Compiling want v0.2.0
[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]    Compiling want v0.3.0
[INFO] [stderr]    Compiling crossbeam-channel v0.4.2
[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" "d86c6e6923e13036977a91527b9bbe514332ee67114372488b7737cf69202037", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d86c6e6923e13036977a91527b9bbe514332ee67114372488b7737cf69202037", kill_on_drop: false }`
[INFO] [stdout] d86c6e6923e13036977a91527b9bbe514332ee67114372488b7737cf69202037