[INFO] fetching crate mech-server 0.0.4...
[INFO] testing mech-server-0.0.4 against 1.47.0 for beta-1.48-1
[INFO] extracting crate mech-server 0.0.4 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate mech-server 0.0.4 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mech-server 0.0.4
[INFO] finished tweaking crates.io crate mech-server 0.0.4
[INFO] tweaked toml for crates.io crate mech-server 0.0.4 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 106f36a18d4ebc6e34432285327ccbf546ef2aca85f7dea7b7e895d917570cf6
[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" "106f36a18d4ebc6e34432285327ccbf546ef2aca85f7dea7b7e895d917570cf6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "106f36a18d4ebc6e34432285327ccbf546ef2aca85f7dea7b7e895d917570cf6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "106f36a18d4ebc6e34432285327ccbf546ef2aca85f7dea7b7e895d917570cf6", kill_on_drop: false }`
[INFO] [stdout] 106f36a18d4ebc6e34432285327ccbf546ef2aca85f7dea7b7e895d917570cf6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2f7023ae6756c97119c89f184f7adb7f4777810580d983ab0c1fcd93912ae9f2
[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" "2f7023ae6756c97119c89f184f7adb7f4777810580d983ab0c1fcd93912ae9f2", 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] [stderr]    Compiling version_check v0.9.2
[INFO] [stderr]    Compiling either v1.6.1
[INFO] [stderr]    Compiling slab v0.4.2
[INFO] [stderr]    Compiling serde v1.0.117
[INFO] [stderr]    Compiling fnv v1.0.7
[INFO] [stderr]    Compiling httparse v1.3.4
[INFO] [stderr]    Compiling siphasher v0.2.3
[INFO] [stderr]    Compiling traitobject v0.1.0
[INFO] [stderr]    Compiling foreign-types-shared v0.1.1
[INFO] [stderr]    Compiling openssl v0.10.30
[INFO] [stderr]    Compiling hashbrown v0.9.1
[INFO] [stderr]    Compiling percent-encoding v2.1.0
[INFO] [stderr]    Compiling regex-syntax v0.6.20
[INFO] [stderr]    Compiling lexical-core v0.7.4
[INFO] [stderr]    Compiling safemem v0.3.3
[INFO] [stderr]    Compiling try-lock v0.2.3
[INFO] [stderr]    Compiling native-tls v0.2.4
[INFO] [stderr]    Compiling encoding_rs v0.8.24
[INFO] [stderr]    Compiling arrayvec v0.5.1
[INFO] [stderr]    Compiling openssl-probe v0.1.2
[INFO] [stderr]    Compiling typeable v0.1.2
[INFO] [stderr]    Compiling language-tags v0.2.2
[INFO] [stderr]    Compiling static_assertions v1.1.0
[INFO] [stderr]    Compiling modifier v0.1.0
[INFO] [stderr]    Compiling dtoa v0.4.6
[INFO] [stderr]    Compiling mime v0.3.16
[INFO] [stderr]    Compiling lazycell v1.3.0
[INFO] [stderr]    Compiling sequence_trie v0.3.6
[INFO] [stderr]    Compiling term v0.4.6
[INFO] [stderr]    Compiling same-file v0.1.3
[INFO] [stderr]    Compiling try_from v0.3.2
[INFO] [stderr]    Compiling unicase v1.4.2
[INFO] [stderr]    Compiling indexmap v1.6.0
[INFO] [stderr]    Compiling openssl-sys v0.9.58
[INFO] [stderr]    Compiling foreign-types v0.3.2
[INFO] [stderr]    Compiling unsafe-any v0.4.2
[INFO] [stderr]    Compiling tokio-sync v0.1.8
[INFO] [stderr]    Compiling rand_isaac v0.1.1
[INFO] [stderr]    Compiling rand_xorshift v0.1.1
[INFO] [stderr]    Compiling rand_hc v0.1.0
[INFO] [stderr]    Compiling idna v0.2.0
[INFO] [stderr]    Compiling walkdir v1.0.7
[INFO] [stderr]    Compiling typemap v0.3.3
[INFO] [stderr]    Compiling iovec v0.1.4
[INFO] [stderr]    Compiling net2 v0.2.35
[INFO] [stderr]    Compiling base64 v0.9.3
[INFO] [stderr]    Compiling base64 v0.10.1
[INFO] [stderr]    Compiling log v0.3.9
[INFO] [stderr]    Compiling want v0.2.0
[INFO] [stderr]    Compiling hyper v0.12.35
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling hashbrown v0.7.2
[INFO] [stderr]    Compiling unicase v2.6.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable 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 error-chain v0.12.4
[INFO] [stderr]    Compiling nom v5.1.2
[INFO] [stderr]    Compiling futures-cpupool v0.1.8
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]    Compiling term-painter v0.2.4
[INFO] [stderr]    Compiling plugin v0.2.6
[INFO] [stderr]    Compiling mime v0.2.6
[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" "2f7023ae6756c97119c89f184f7adb7f4777810580d983ab0c1fcd93912ae9f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2f7023ae6756c97119c89f184f7adb7f4777810580d983ab0c1fcd93912ae9f2", kill_on_drop: false }`
[INFO] [stdout] 2f7023ae6756c97119c89f184f7adb7f4777810580d983ab0c1fcd93912ae9f2
