[INFO] fetching crate mmtk 0.6.0...
[INFO] testing mmtk-0.6.0 against 1.55.0 for beta-1.56-1
[INFO] extracting crate mmtk 0.6.0 into /workspace/builds/worker-78/source
[INFO] validating manifest of crates.io crate mmtk 0.6.0 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-78/source/rust-toolchain
[INFO] started tweaking crates.io crate mmtk 0.6.0
[INFO] finished tweaking crates.io crate mmtk 0.6.0
[INFO] tweaked toml for crates.io crate mmtk 0.6.0 written to /workspace/builds/worker-78/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-78/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-78/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6575b6fed3c8c9aeedb5d89f8e2c4df70ed5d87181680ba5b5d3e66d026993dc
[INFO] running `Command { std: "docker" "start" "-a" "6575b6fed3c8c9aeedb5d89f8e2c4df70ed5d87181680ba5b5d3e66d026993dc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6575b6fed3c8c9aeedb5d89f8e2c4df70ed5d87181680ba5b5d3e66d026993dc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6575b6fed3c8c9aeedb5d89f8e2c4df70ed5d87181680ba5b5d3e66d026993dc", kill_on_drop: false }`
[INFO] [stdout] 6575b6fed3c8c9aeedb5d89f8e2c4df70ed5d87181680ba5b5d3e66d026993dc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-78/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-78/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4caac9fa4e8ab0dce12d32a10b71c527d82d096d7fe3be90e7846a73dc4a7a49
[INFO] running `Command { std: "docker" "start" "-a" "4caac9fa4e8ab0dce12d32a10b71c527d82d096d7fe3be90e7846a73dc4a7a49", kill_on_drop: false }`
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]    Compiling syn v1.0.76
[INFO] [stderr]    Compiling nodrop v0.1.14
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling regex-syntax v0.6.25
[INFO] [stderr]    Compiling array-macro v1.0.5
[INFO] [stderr]    Compiling humantime v2.1.0
[INFO] [stderr]    Compiling enum_derive v0.1.7
[INFO] [stderr]    Compiling atomic v0.4.6
[INFO] [stderr]    Compiling downcast-rs v1.2.0
[INFO] [stderr]    Compiling custom_derive v0.1.7
[INFO] [stderr]    Compiling memoffset v0.5.6
[INFO] [stderr]    Compiling crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling atomic-traits v0.2.0
[INFO] [stderr]    Compiling crossbeam-epoch v0.7.2
[INFO] [stderr]    Compiling crossbeam-deque v0.6.3
[INFO] [stderr]    Compiling regex v1.5.4
[INFO] [stderr]    Compiling env_logger v0.8.4
[INFO] [stderr]    Compiling enum-map-derive v0.4.6
[INFO] [stderr]    Compiling enum-map v0.6.4
[INFO] [stderr]    Compiling mmtk v0.6.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(asm)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(integer_atomics)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:4:1
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(is_sorted)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![feature(drain_filter)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(nll)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(box_syntax)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:8:1
[INFO] [stdout]   |
[INFO] [stdout] 8 | #![feature(maybe_uninit_ref)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(maybe_uninit_extra)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:10:1
[INFO] [stdout]    |
[INFO] [stdout] 10 | #![feature(get_mut_unchecked)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:11:1
[INFO] [stdout]    |
[INFO] [stdout] 11 | #![feature(arbitrary_self_types)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:12:1
[INFO] [stdout]    |
[INFO] [stdout] 12 | #![feature(associated_type_defaults)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:13:1
[INFO] [stdout]    |
[INFO] [stdout] 13 | #![feature(specialization)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:14:1
[INFO] [stdout]    |
[INFO] [stdout] 14 | #![feature(trait_alias)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:15:1
[INFO] [stdout]    |
[INFO] [stdout] 15 | #![feature(const_panic)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:16:1
[INFO] [stdout]    |
[INFO] [stdout] 16 | #![feature(const_fn_union)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:17:1
[INFO] [stdout]    |
[INFO] [stdout] 17 | #![feature(step_trait)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:18:1
[INFO] [stdout]    |
[INFO] [stdout] 18 | #![feature(step_trait_ext)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:19:1
[INFO] [stdout]    |
[INFO] [stdout] 19 | #![feature(const_generics)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0199]: implementing the trait `Step` is not unsafe
[INFO] [stdout]    --> src/policy/immix/block.rs:307:1
[INFO] [stdout]     |
[INFO] [stdout] 307 | / unsafe impl Step for Block {
[INFO] [stdout] 308 | |     /// Get the number of blocks between the given two blocks.
[INFO] [stdout] 309 | |     #[inline(always)]
[INFO] [stdout] 310 | |     #[allow(clippy::assertions_on_constants)]
[INFO] [stdout] ...   |
[INFO] [stdout] 343 | |     }
[INFO] [stdout] 344 | | }
[INFO] [stdout]     | |_^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0199]: implementing the trait `Step` is not unsafe
[INFO] [stdout]    --> src/policy/immix/chunk.rs:83:1
[INFO] [stdout]     |
[INFO] [stdout] 83  | / unsafe impl Step for Chunk {
[INFO] [stdout] 84  | |     /// Get the number of chunks between the given two chunks.
[INFO] [stdout] 85  | |     #[inline(always)]
[INFO] [stdout] 86  | |     fn steps_between(start: &Self, end: &Self) -> Option<usize> {
[INFO] [stdout] ...   |
[INFO] [stdout] 117 | |     }
[INFO] [stdout] 118 | | }
[INFO] [stdout]     | |_^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0199]: implementing the trait `Step` is not unsafe
[INFO] [stdout]    --> src/policy/immix/line.rs:116:1
[INFO] [stdout]     |
[INFO] [stdout] 116 | / unsafe impl Step for Line {
[INFO] [stdout] 117 | |     /// Get the number of lines between the given two lines.
[INFO] [stdout] 118 | |     #[inline(always)]
[INFO] [stdout] 119 | |     fn steps_between(start: &Self, end: &Self) -> Option<usize> {
[INFO] [stdout] ...   |
[INFO] [stdout] 155 | |     }
[INFO] [stdout] 156 | | }
[INFO] [stdout]     | |_^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 21 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0199, E0554.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0199`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `mmtk` due to 22 previous errors
[INFO] running `Command { std: "docker" "inspect" "4caac9fa4e8ab0dce12d32a10b71c527d82d096d7fe3be90e7846a73dc4a7a49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4caac9fa4e8ab0dce12d32a10b71c527d82d096d7fe3be90e7846a73dc4a7a49", kill_on_drop: false }`
[INFO] [stdout] 4caac9fa4e8ab0dce12d32a10b71c527d82d096d7fe3be90e7846a73dc4a7a49