[INFO] crate rust-freqdist 0.1.5 is already in cache
[INFO] testing rust-freqdist-0.1.5 against beta-2020-07-24 for beta-1.46-1
[INFO] extracting crate rust-freqdist 0.1.5 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate rust-freqdist 0.1.5 on toolchain beta-2020-07-24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rust-freqdist 0.1.5
[INFO] finished tweaking crates.io crate rust-freqdist 0.1.5
[INFO] tweaked toml for crates.io crate rust-freqdist 0.1.5 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 752e573ce3ec9827c35a26b7637054432107b86bb9a30d7d73352c3045c17053
[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" "752e573ce3ec9827c35a26b7637054432107b86bb9a30d7d73352c3045c17053", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "752e573ce3ec9827c35a26b7637054432107b86bb9a30d7d73352c3045c17053", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "752e573ce3ec9827c35a26b7637054432107b86bb9a30d7d73352c3045c17053", kill_on_drop: false }`
[INFO] [stdout] 752e573ce3ec9827c35a26b7637054432107b86bb9a30d7d73352c3045c17053
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 599aa061165a7ab9a7cf3f4921ce90fff13e7fa9534159e0752d53940ab31f15
[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" "599aa061165a7ab9a7cf3f4921ce90fff13e7fa9534159e0752d53940ab31f15", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust-freqdist v0.1.5 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.43s
[INFO] running `Command { std: "docker" "inspect" "599aa061165a7ab9a7cf3f4921ce90fff13e7fa9534159e0752d53940ab31f15", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "599aa061165a7ab9a7cf3f4921ce90fff13e7fa9534159e0752d53940ab31f15", kill_on_drop: false }`
[INFO] [stdout] 599aa061165a7ab9a7cf3f4921ce90fff13e7fa9534159e0752d53940ab31f15
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4115415ee4849eb03f970859d6ce642239d8ea910262f34086f6bf4340ff1daf
[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" "4115415ee4849eb03f970859d6ce642239d8ea910262f34086f6bf4340ff1daf", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust-freqdist v0.1.5 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:29:19
[INFO] [stdout]    |
[INFO] [stdout] 29 | #![cfg_attr(test, feature(test))]
[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 `rust-freqdist`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "4115415ee4849eb03f970859d6ce642239d8ea910262f34086f6bf4340ff1daf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4115415ee4849eb03f970859d6ce642239d8ea910262f34086f6bf4340ff1daf", kill_on_drop: false }`
[INFO] [stdout] 4115415ee4849eb03f970859d6ce642239d8ea910262f34086f6bf4340ff1daf