[INFO] fetching crate string-err 0.1.1...
[INFO] checking string-err-0.1.1 against beta-2020-07-24 for pr-75494-beta
[INFO] extracting crate string-err 0.1.1 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate string-err 0.1.1 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 string-err 0.1.1
[INFO] finished tweaking crates.io crate string-err 0.1.1
[INFO] tweaked toml for crates.io crate string-err 0.1.1 written to /workspace/builds/worker-5/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-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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5040c5a81370e53ef8aa9a0954b3c4a54c2bf606fc28a2a505b8a9b8b00963c5
[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" "5040c5a81370e53ef8aa9a0954b3c4a54c2bf606fc28a2a505b8a9b8b00963c5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5040c5a81370e53ef8aa9a0954b3c4a54c2bf606fc28a2a505b8a9b8b00963c5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5040c5a81370e53ef8aa9a0954b3c4a54c2bf606fc28a2a505b8a9b8b00963c5", kill_on_drop: false }`
[INFO] [stdout] 5040c5a81370e53ef8aa9a0954b3c4a54c2bf606fc28a2a505b8a9b8b00963c5
[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=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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 210bd020046736f5c8efdff979dbac34854b69117f48b575e41c8bca685c7791
[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" "210bd020046736f5c8efdff979dbac34854b69117f48b575e41c8bca685c7791", kill_on_drop: false }`
[INFO] [stderr]     Checking string-err v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:18:1
[INFO] [stdout]    |
[INFO] [stdout] 18 | / #![feature(
[INFO] [stdout] 19 | |     specialization,
[INFO] [stdout] 20 | |     backtrace,
[INFO] [stdout] 21 | |     debug_non_exhaustive,
[INFO] [stdout] 22 | |     external_doc,
[INFO] [stdout] 23 | |     try_trait,
[INFO] [stdout] 24 | | )]
[INFO] [stdout]    | |__^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]   --> src/lib.rs:19:2
[INFO] [stdout]    |
[INFO] [stdout] 19 |     specialization,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:18:1
[INFO] [stdout]    |
[INFO] [stdout] 18 | / #![feature(
[INFO] [stdout] 19 | |     specialization,
[INFO] [stdout] 20 | |     backtrace,
[INFO] [stdout] 21 | |     debug_non_exhaustive,
[INFO] [stdout] 22 | |     external_doc,
[INFO] [stdout] 23 | |     try_trait,
[INFO] [stdout] 24 | | )]
[INFO] [stdout]    | |__^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]   --> src/lib.rs:19:2
[INFO] [stdout]    |
[INFO] [stdout] 19 |     specialization,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `string-err`.
[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] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "210bd020046736f5c8efdff979dbac34854b69117f48b575e41c8bca685c7791", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "210bd020046736f5c8efdff979dbac34854b69117f48b575e41c8bca685c7791", kill_on_drop: false }`
[INFO] [stdout] 210bd020046736f5c8efdff979dbac34854b69117f48b575e41c8bca685c7791
