[INFO] fetching crate rxrust 0.8.3...
[INFO] checking rxrust-0.8.3 against beta-2020-07-24 for pr-75494-beta
[INFO] extracting crate rxrust 0.8.3 into /workspace/builds/worker-10/source
[INFO] validating manifest of crates.io crate rxrust 0.8.3 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 rxrust 0.8.3
[INFO] finished tweaking crates.io crate rxrust 0.8.3
[INFO] tweaked toml for crates.io crate rxrust 0.8.3 written to /workspace/builds/worker-10/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-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] 92b2f901ea3de014c08d204bfee565ff846cef8bd59df789cdaa3524adf5a4a4
[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" "92b2f901ea3de014c08d204bfee565ff846cef8bd59df789cdaa3524adf5a4a4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "92b2f901ea3de014c08d204bfee565ff846cef8bd59df789cdaa3524adf5a4a4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "92b2f901ea3de014c08d204bfee565ff846cef8bd59df789cdaa3524adf5a4a4", kill_on_drop: false }`
[INFO] [stdout] 92b2f901ea3de014c08d204bfee565ff846cef8bd59df789cdaa3524adf5a4a4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] ec540f6f2a04a143e31ad4a43dfc9e082b683a9434a4c0b9e55aed976ed58f7a
[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" "ec540f6f2a04a143e31ad4a43dfc9e082b683a9434a4c0b9e55aed976ed58f7a", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking float-cmp v0.5.3
[INFO] [stderr]     Checking futures-executor-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking futures-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking futures-timer v0.3.0
[INFO] [stderr]     Checking rxrust v0.8.3 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(external_doc, specialization, drain_filter, test, decl_macro)]
[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:1:26
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(external_doc, specialization, drain_filter, test, decl_macro)]
[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:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(external_doc, specialization, drain_filter, test, decl_macro)]
[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:1:26
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(external_doc, specialization, drain_filter, test, decl_macro)]
[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: 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: could not compile `rxrust`.
[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" "ec540f6f2a04a143e31ad4a43dfc9e082b683a9434a4c0b9e55aed976ed58f7a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ec540f6f2a04a143e31ad4a43dfc9e082b683a9434a4c0b9e55aed976ed58f7a", kill_on_drop: false }`
[INFO] [stdout] ec540f6f2a04a143e31ad4a43dfc9e082b683a9434a4c0b9e55aed976ed58f7a
