[INFO] fetching crate mutagen 0.1.2...
[INFO] testing mutagen-0.1.2 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate mutagen 0.1.2 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate mutagen 0.1.2 on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mutagen 0.1.2
[INFO] finished tweaking crates.io crate mutagen 0.1.2
[INFO] tweaked toml for crates.io crate mutagen 0.1.2 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5b553cb1c8515f49c73e1a78f10556af224448c9007cc35bd0afe15abba48fac
[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" "5b553cb1c8515f49c73e1a78f10556af224448c9007cc35bd0afe15abba48fac", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5b553cb1c8515f49c73e1a78f10556af224448c9007cc35bd0afe15abba48fac", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5b553cb1c8515f49c73e1a78f10556af224448c9007cc35bd0afe15abba48fac", kill_on_drop: false }`
[INFO] [stdout] 5b553cb1c8515f49c73e1a78f10556af224448c9007cc35bd0afe15abba48fac
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f9b020d260b5c03f949ac777cf8787071cc087ccff8b5eea17f110a8f702936d
[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" "f9b020d260b5c03f949ac777cf8787071cc087ccff8b5eea17f110a8f702936d", kill_on_drop: false }`
[INFO] [stderr]    Compiling mutagen v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> build.rs:6:26
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn write_binop(out: &mut Write, o_trait: &str, o_fn: &str, mut_trait: &str, mut_fn: &str) ->
[INFO] [stdout]   |                          ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> build.rs:68:25
[INFO] [stdout]    |
[INFO] [stdout] 68 | fn write_unop(out: &mut Write, op_trait: &str, op_fn: &str) -> Result<()> {
[INFO] [stdout]    |                         ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[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(specialization, atomic_min_max, try_from, assoc_unix_epoch)]
[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:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(specialization, atomic_min_max, try_from, assoc_unix_epoch)]
[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]   = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:143:72
[INFO] [stdout]     |
[INFO] [stdout] 143 |     pub fn forloop<'a, I: Iterator + 'a>(&self, i: I, n: usize) -> Box<Iterator<Item=I::Item> + 'a> {
[INFO] [stdout]     |                                                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item=I::Item> + 'a`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:216:94
[INFO] [stdout]     |
[INFO] [stdout] 216 | pub fn forloop<'a, I: Iterator + 'a>(i: I, n: usize, flag: &AtomicUsize, mask: usize) -> Box<Iterator<Item=I::Item > + 'a> {
[INFO] [stdout]     |                                                                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item=I::Item > + 'a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 3 warnings 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 `mutagen`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "f9b020d260b5c03f949ac777cf8787071cc087ccff8b5eea17f110a8f702936d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f9b020d260b5c03f949ac777cf8787071cc087ccff8b5eea17f110a8f702936d", kill_on_drop: false }`
[INFO] [stdout] f9b020d260b5c03f949ac777cf8787071cc087ccff8b5eea17f110a8f702936d