[INFO] fetching crate mantle-build 0.2.2...
[INFO] testing mantle-build-0.2.2 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate mantle-build 0.2.2 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate mantle-build 0.2.2 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 mantle-build 0.2.2
[INFO] finished tweaking crates.io crate mantle-build 0.2.2
[INFO] tweaked toml for crates.io crate mantle-build 0.2.2 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate crates.io crate mantle-build 0.2.2 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 serde_cbor v0.9.0
[INFO] [stderr]   Downloaded backtrace v0.3.32
[INFO] [stderr]   Downloaded cc v1.0.37
[INFO] [stderr]   Downloaded rustc-demangle v0.1.15
[INFO] [stderr]   Downloaded autocfg v0.1.4
[INFO] [stderr]   Downloaded default-env v0.1.1
[INFO] [stderr]   Downloaded rustfix v0.4.5
[INFO] [stderr]   Downloaded filetime v0.2.6
[INFO] [stderr]   Downloaded mantle-rpc v0.1.1
[INFO] [stderr]   Downloaded log v0.4.6
[INFO] [stderr]   Downloaded crossbeam-epoch v0.7.1
[INFO] [stderr]   Downloaded quote v0.6.12
[INFO] [stderr]   Downloaded miow v0.3.3
[INFO] [stderr]   Downloaded regex-syntax v0.6.7
[INFO] [stderr]   Downloaded arrayvec v0.4.10
[INFO] [stderr]   Downloaded half v1.3.0
[INFO] [stderr]   Downloaded serde_derive v1.0.94
[INFO] [stderr]   Downloaded blockchain-traits v0.2.0
[INFO] [stderr]   Downloaded toml v0.5.1
[INFO] [stderr]   Downloaded backtrace-sys v0.1.30
[INFO] [stderr]   Downloaded socket2 v0.3.9
[INFO] [stderr]   Downloaded proc-macro-hack v0.5.8
[INFO] [stderr]   Downloaded getopts v0.2.19
[INFO] [stderr]   Downloaded regex v1.1.8
[INFO] [stderr]   Downloaded libflate v0.1.25
[INFO] [stderr]   Downloaded compiletest_rs v0.3.22
[INFO] [stderr]   Downloaded mantle v0.2.0
[INFO] [stderr]   Downloaded serde v1.0.94
[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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/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] ab2019dc889f64cf0fde0680cdc55f36cdf7a57a6f7764e5ef6b83b8c4971fae
[INFO] running `Command { std: "docker" "start" "-a" "ab2019dc889f64cf0fde0680cdc55f36cdf7a57a6f7764e5ef6b83b8c4971fae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ab2019dc889f64cf0fde0680cdc55f36cdf7a57a6f7764e5ef6b83b8c4971fae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ab2019dc889f64cf0fde0680cdc55f36cdf7a57a6f7764e5ef6b83b8c4971fae", kill_on_drop: false }`
[INFO] [stdout] ab2019dc889f64cf0fde0680cdc55f36cdf7a57a6f7764e5ef6b83b8c4971fae
[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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fb0b592bdbec150aefd7f3ed1cc96018f1ead6cac94b0ccf43d5b184c862e215
[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" "fb0b592bdbec150aefd7f3ed1cc96018f1ead6cac94b0ccf43d5b184c862e215", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling syn v0.15.39
[INFO] [stderr]    Compiling libc v0.2.58
[INFO] [stderr]    Compiling cfg-if v0.1.9
[INFO] [stderr]    Compiling spin v0.5.0
[INFO] [stderr]    Compiling arrayvec v0.4.10
[INFO] [stderr]    Compiling nodrop v0.1.13
[INFO] [stderr]    Compiling scopeguard v0.3.3
[INFO] [stderr]    Compiling memoffset v0.2.1
[INFO] [stderr]    Compiling autocfg v0.1.4
[INFO] [stderr]    Compiling cc v1.0.37
[INFO] [stderr]    Compiling rayon-core v1.5.0
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]    Compiling serde v1.0.94
[INFO] [stderr]    Compiling byteorder v1.3.2
[INFO] [stderr]    Compiling either v1.5.2
[INFO] [stderr]    Compiling unicode-segmentation v1.3.0
[INFO] [stderr]    Compiling smallvec v0.6.10
[INFO] [stderr]    Compiling cgmath v0.16.1
[INFO] [stderr]    Compiling crc32fast v1.2.0
[INFO] [stderr]    Compiling rustc-demangle v0.1.15
[INFO] [stderr]    Compiling winapi v0.3.7
[INFO] [stderr]    Compiling matches v0.1.8
[INFO] [stderr]    Compiling ryu v1.0.0
[INFO] [stderr]    Compiling approx v0.1.1
[INFO] [stderr]    Compiling itoa v0.4.4
[INFO] [stderr]    Compiling rgb v0.8.13
[INFO] [stderr]    Compiling wasmparser v0.30.0
[INFO] [stderr]    Compiling take_mut v0.2.2
[INFO] [stderr]    Compiling percent-encoding v1.0.1
[INFO] [stderr]    Compiling adler32 v1.0.3
[INFO] [stderr]    Compiling rle-decode-fast v1.0.1
[INFO] [stderr]    Compiling leb128 v0.2.4
[INFO] [stderr]    Compiling log v0.4.6
[INFO] [stderr]    Compiling lazy_static v1.3.0
[INFO] [stderr]    Compiling unicode-normalization v0.1.8
[INFO] [stderr]    Compiling unicode-bidi v0.3.4
[INFO] [stderr]    Compiling num-traits v0.2.8
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]    Compiling crossbeam-utils v0.6.5
[INFO] [stderr]    Compiling libflate v0.1.25
[INFO] [stderr]    Compiling crossbeam-epoch v0.7.1
[INFO] [stderr]    Compiling crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]    Compiling num_cpus v1.10.1
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]    Compiling backtrace-sys v0.1.30
[INFO] [stderr]    Compiling crossbeam-deque v0.6.3
[INFO] [stderr]    Compiling idna v0.1.5
[INFO] [stderr]    Compiling backtrace v0.3.32
[INFO] [stderr]    Compiling rayon v1.1.0
[INFO] [stderr]    Compiling url v1.7.2
[INFO] [stderr]    Compiling num-traits v0.1.43
[INFO] [stderr]    Compiling id-arena v2.2.1
[INFO] [stderr]    Compiling winconsole v0.10.0
[INFO] [stderr]    Compiling colored v1.8.0
[INFO] [stderr]    Compiling synstructure v0.10.2
[INFO] [stderr]    Compiling serde_derive v1.0.94
[INFO] [stderr]    Compiling proc-macro-hack v0.5.8
[INFO] [stderr]    Compiling walrus-macro v0.8.0
[INFO] [stderr]    Compiling failure v0.1.5
[INFO] [stderr]    Compiling proc-quote-impl v0.2.2
[INFO] [stderr]    Compiling proc-quote v0.2.2
[INFO] [stderr]    Compiling walrus v0.8.0
[INFO] [stderr]    Compiling serde_json v1.0.40
[INFO] [stderr]    Compiling toml v0.5.1
[INFO] [stderr]    Compiling mantle-rpc v0.1.1
[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/mantle-rpc-0.1.1/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(box_syntax)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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 `mantle-rpc`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "fb0b592bdbec150aefd7f3ed1cc96018f1ead6cac94b0ccf43d5b184c862e215", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fb0b592bdbec150aefd7f3ed1cc96018f1ead6cac94b0ccf43d5b184c862e215", kill_on_drop: false }`
[INFO] [stdout] fb0b592bdbec150aefd7f3ed1cc96018f1ead6cac94b0ccf43d5b184c862e215