[INFO] fetching crate generic-channel 0.2.0...
[INFO] checking generic-channel-0.2.0 against master#c724b67e1b474262917a5154d74e7072267593fe for pr-74315
[INFO] extracting crate generic-channel 0.2.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate generic-channel 0.2.0 on toolchain c724b67e1b474262917a5154d74e7072267593fe
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "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-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "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] 8b78dcba6bbc054dfb37f96e6f9a07e64890cde963c81034f733872f580bbe0c
[INFO] running `Command { std: "docker" "start" "-a" "8b78dcba6bbc054dfb37f96e6f9a07e64890cde963c81034f733872f580bbe0c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8b78dcba6bbc054dfb37f96e6f9a07e64890cde963c81034f733872f580bbe0c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8b78dcba6bbc054dfb37f96e6f9a07e64890cde963c81034f733872f580bbe0c", kill_on_drop: false }`
[INFO] [stdout] 8b78dcba6bbc054dfb37f96e6f9a07e64890cde963c81034f733872f580bbe0c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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=forbid" "-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:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c9f62cce2fca642edb71a1d8dd1e6ab2351a78d6cd61fcff8a80ae17964794af
[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" "c9f62cce2fca642edb71a1d8dd1e6ab2351a78d6cd61fcff8a80ae17964794af", kill_on_drop: false }`
[INFO] [stderr]     Checking futures v0.1.29
[INFO] [stderr]     Checking generic-channel v0.2.0 (/opt/rustwide/workdir)
[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] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0596`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `generic-channel`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "c9f62cce2fca642edb71a1d8dd1e6ab2351a78d6cd61fcff8a80ae17964794af", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c9f62cce2fca642edb71a1d8dd1e6ab2351a78d6cd61fcff8a80ae17964794af", kill_on_drop: false }`
[INFO] [stdout] c9f62cce2fca642edb71a1d8dd1e6ab2351a78d6cd61fcff8a80ae17964794af