[INFO] fetching crate serde_single_or_vec 1.0.1...
[INFO] checking serde_single_or_vec-1.0.1 against master#36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923 for pr-81863
[INFO] extracting crate serde_single_or_vec 1.0.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate serde_single_or_vec 1.0.1 on toolchain 36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate serde_single_or_vec 1.0.1
[INFO] finished tweaking crates.io crate serde_single_or_vec 1.0.1
[INFO] tweaked toml for crates.io crate serde_single_or_vec 1.0.1 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:ce6408862c0f4858e6cd2b85b2cf085ff7d0d6323904d0a94b71664a228554ab" "/opt/rustwide/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "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] 0eb11367de595e571a261027ac1b3859efbbfeedbad23c996f7d656f80915fe4
[INFO] running `Command { std: "docker" "start" "-a" "0eb11367de595e571a261027ac1b3859efbbfeedbad23c996f7d656f80915fe4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0eb11367de595e571a261027ac1b3859efbbfeedbad23c996f7d656f80915fe4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0eb11367de595e571a261027ac1b3859efbbfeedbad23c996f7d656f80915fe4", kill_on_drop: false }`
[INFO] [stdout] 0eb11367de595e571a261027ac1b3859efbbfeedbad23c996f7d656f80915fe4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:ce6408862c0f4858e6cd2b85b2cf085ff7d0d6323904d0a94b71664a228554ab" "/opt/rustwide/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "check" "--frozen" "--all" "--all-targets" "--message-format=json", 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] 10f1faf3b98aef314d0fce7dd8ff71675e0bab8f3b407f1bdeb6b41beeb0730f
[INFO] running `Command { std: "docker" "start" "-a" "10f1faf3b98aef314d0fce7dd8ff71675e0bab8f3b407f1bdeb6b41beeb0730f", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.60
[INFO] [stderr]    Compiling serde_derive v1.0.123
[INFO] [stderr]    Compiling serde v1.0.123
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling serde_json v1.0.62
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]    Compiling quote v1.0.8
[INFO] [stderr]     Checking arrayvec v0.5.2
[INFO] [stderr]     Checking serde_single_or_vec v1.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0603]: module `private` is private
[INFO] [stdout]    --> src/lib.rs:183:5
[INFO] [stdout]     |
[INFO] [stdout] 183 |     private::de::{Content, ContentRefDeserializer},
[INFO] [stdout]     |     ^^^^^^^ private module
[INFO] [stdout]     |
[INFO] [stdout] note: the module `private` is defined here
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/serde-1.0.123/src/lib.rs:277:5
[INFO] [stdout]     |
[INFO] [stdout] 277 | use self::__private as private;
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0603`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `serde_single_or_vec`
[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] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "10f1faf3b98aef314d0fce7dd8ff71675e0bab8f3b407f1bdeb6b41beeb0730f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "10f1faf3b98aef314d0fce7dd8ff71675e0bab8f3b407f1bdeb6b41beeb0730f", kill_on_drop: false }`
[INFO] [stdout] 10f1faf3b98aef314d0fce7dd8ff71675e0bab8f3b407f1bdeb6b41beeb0730f