[INFO] fetching crate rust_icu_ustring 0.4.1...
[INFO] testing rust_icu_ustring-0.4.1 against 1.49.0 for beta-1.50-1
[INFO] extracting crate rust_icu_ustring 0.4.1 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate rust_icu_ustring 0.4.1 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rust_icu_ustring 0.4.1
[INFO] finished tweaking crates.io crate rust_icu_ustring 0.4.1
[INFO] tweaked toml for crates.io crate rust_icu_ustring 0.4.1 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "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] fd5581d44902b5914fc412b9a63cce506eb2becf802b11fbc5c7084a05956871
[INFO] running `Command { std: "docker" "start" "-a" "fd5581d44902b5914fc412b9a63cce506eb2becf802b11fbc5c7084a05956871", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fd5581d44902b5914fc412b9a63cce506eb2becf802b11fbc5c7084a05956871", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fd5581d44902b5914fc412b9a63cce506eb2becf802b11fbc5c7084a05956871", kill_on_drop: false }`
[INFO] [stdout] fd5581d44902b5914fc412b9a63cce506eb2becf802b11fbc5c7084a05956871
[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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a40ec13a766bfaa275886b6be6d8f6c166ae15ad4620f7b51d10bb73b7516d13
[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" "a40ec13a766bfaa275886b6be6d8f6c166ae15ad4620f7b51d10bb73b7516d13", kill_on_drop: false }`
[INFO] [stderr]    Compiling paste v1.0.4
[INFO] [stderr]    Compiling nom v5.1.2
[INFO] [stderr]    Compiling clang-sys v0.29.3
[INFO] [stderr]    Compiling cexpr v0.4.0
[INFO] [stderr]    Compiling bindgen v0.53.3
[INFO] [stderr]    Compiling rust_icu_sys v0.4.1
[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/rust_icu_sys-0.4.1/build.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(try_trait)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_icu_sys`
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "a40ec13a766bfaa275886b6be6d8f6c166ae15ad4620f7b51d10bb73b7516d13", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a40ec13a766bfaa275886b6be6d8f6c166ae15ad4620f7b51d10bb73b7516d13", kill_on_drop: false }`
[INFO] [stdout] a40ec13a766bfaa275886b6be6d8f6c166ae15ad4620f7b51d10bb73b7516d13