[INFO] fetching crate ffi-std 0.1.0...
[INFO] checking ffi-std-0.1.0 against master#d62d3f7fa9a91d933213cc10e20e740608983f64 for pr-77015
[INFO] extracting crate ffi-std 0.1.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate ffi-std 0.1.0 on toolchain d62d3f7fa9a91d933213cc10e20e740608983f64
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ffi-std 0.1.0
[INFO] finished tweaking crates.io crate ffi-std 0.1.0
[INFO] tweaked toml for crates.io crate ffi-std 0.1.0 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "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" "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" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e213dea04a28927e94efe05fa0ed9d1bdcf34d1eaf63afb2de9a9316df94e952
[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" "e213dea04a28927e94efe05fa0ed9d1bdcf34d1eaf63afb2de9a9316df94e952", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e213dea04a28927e94efe05fa0ed9d1bdcf34d1eaf63afb2de9a9316df94e952", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e213dea04a28927e94efe05fa0ed9d1bdcf34d1eaf63afb2de9a9316df94e952", kill_on_drop: false }`
[INFO] [stdout] e213dea04a28927e94efe05fa0ed9d1bdcf34d1eaf63afb2de9a9316df94e952
[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" "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" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8721244842a7b81bf38bd3dc1d34c93519950901ca091b757d6962519c6944a0
[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" "8721244842a7b81bf38bd3dc1d34c93519950901ca091b757d6962519c6944a0", kill_on_drop: false }`
[INFO] [stderr]     Checking ffi-std v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0658]: mutable references are not allowed in constant functions
[INFO] [stdout]   --> src/lib.rs:39:44
[INFO] [stdout]    |
[INFO] [stdout] 39 |     pub const unsafe fn get_mut(&mut self) -> &mut T {
[INFO] [stdout]    |                                               ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #57349 <https://github.com/rust-lang/rust/issues/57349> for more information
[INFO] [stdout]    = help: add `#![feature(const_mut_refs)]` to the crate attributes to enable
[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 E0658`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ffi-std`
[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] [stdout] error[E0658]: mutable references are not allowed in constant functions
[INFO] [stdout]   --> src/lib.rs:39:44
[INFO] [stdout]    |
[INFO] [stdout] 39 |     pub const unsafe fn get_mut(&mut self) -> &mut T {
[INFO] [stdout]    |                                               ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #57349 <https://github.com/rust-lang/rust/issues/57349> for more information
[INFO] [stdout]    = help: add `#![feature(const_mut_refs)]` to the crate attributes to enable
[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 E0658`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "8721244842a7b81bf38bd3dc1d34c93519950901ca091b757d6962519c6944a0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8721244842a7b81bf38bd3dc1d34c93519950901ca091b757d6962519c6944a0", kill_on_drop: false }`
[INFO] [stdout] 8721244842a7b81bf38bd3dc1d34c93519950901ca091b757d6962519c6944a0