[INFO] fetching crate generic-channel 0.2.0...
[INFO] checking generic-channel-0.2.0 against try#b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f for pr-76104
[INFO] extracting crate generic-channel 0.2.0 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate generic-channel 0.2.0 on toolchain b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate generic-channel 0.2.0
[INFO] finished tweaking crates.io crate generic-channel 0.2.0
[INFO] tweaked toml for crates.io crate generic-channel 0.2.0 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fe842db2f31836e0912407b602ba579b85659f99c74cdf8a49e933b78f349e8b
[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" "fe842db2f31836e0912407b602ba579b85659f99c74cdf8a49e933b78f349e8b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fe842db2f31836e0912407b602ba579b85659f99c74cdf8a49e933b78f349e8b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fe842db2f31836e0912407b602ba579b85659f99c74cdf8a49e933b78f349e8b", kill_on_drop: false }`
[INFO] [stdout] fe842db2f31836e0912407b602ba579b85659f99c74cdf8a49e933b78f349e8b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ce307b452098cce84c5d862c6c9b31c8e8be67b89264a530c3d57124f1fc8e3a
[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" "ce307b452098cce84c5d862c6c9b31c8e8be67b89264a530c3d57124f1fc8e3a", kill_on_drop: false }`
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking generic-channel v0.2.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stderr]     Checking crossbeam-channel v0.3.9
[INFO] [stdout] error[E0596]: cannot borrow `*sender` as mutable, as `sender` is not declared as mutable
[INFO] [stdout]   --> src/lib.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |         let sender: Box<dyn Sender<u8>> = Box::new(sender);
[INFO] [stdout]    |             ------ help: consider changing this to be mutable: `mut sender`
[INFO] [stdout] 54 |         sender.try_send(1).expect("send");
[INFO] [stdout]    |         ^^^^^^ cannot borrow as mutable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0596]: cannot borrow `*sender` as mutable, as `sender` is not declared as mutable
[INFO] [stdout]   --> src/lib.rs:57:20
[INFO] [stdout]    |
[INFO] [stdout] 53 |         let sender: Box<dyn Sender<u8>> = Box::new(sender);
[INFO] [stdout]    |             ------ help: consider changing this to be mutable: `mut sender`
[INFO] [stdout] ...
[INFO] [stdout] 57 |         assert_eq!(sender.try_send(2), Err(TrySendError::Disconnected(2u8)));
[INFO] [stdout]    |                    ^^^^^^ cannot borrow as mutable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `generic-channel`
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0596`.
[INFO] [stdout] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "ce307b452098cce84c5d862c6c9b31c8e8be67b89264a530c3d57124f1fc8e3a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ce307b452098cce84c5d862c6c9b31c8e8be67b89264a530c3d57124f1fc8e3a", kill_on_drop: false }`
[INFO] [stdout] ce307b452098cce84c5d862c6c9b31c8e8be67b89264a530c3d57124f1fc8e3a