[INFO] fetching crate rb_tree 0.5.0...
[INFO] checking rb_tree-0.5.0 against master#39cb3386ddc6c71657418be28dbb3987eea4aa4b for pr-133536
[INFO] extracting crate rb_tree 0.5.0 into /workspace/builds/worker-4-tc1/source
[INFO] validating manifest of crates.io crate rb_tree 0.5.0 on toolchain 39cb3386ddc6c71657418be28dbb3987eea4aa4b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+39cb3386ddc6c71657418be28dbb3987eea4aa4b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rb_tree 0.5.0
[INFO] finished tweaking crates.io crate rb_tree 0.5.0
[INFO] tweaked toml for crates.io crate rb_tree 0.5.0 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate crates.io crate rb_tree 0.5.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+39cb3386ddc6c71657418be28dbb3987eea4aa4b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded serde_derive v1.0.130
[INFO] [stderr]   Downloaded half v1.7.1
[INFO] [stderr]   Downloaded criterion-plot v0.4.4
[INFO] [stderr]   Downloaded serde_json v1.0.68
[INFO] [stderr]   Downloaded semver v1.0.4
[INFO] [stderr]   Downloaded bumpalo v3.7.1
[INFO] [stderr]   Downloaded serde v1.0.130
[INFO] [stderr]   Downloaded itertools v0.10.1
[INFO] [stderr]   Downloaded criterion v0.3.5
[INFO] [stderr]   Downloaded syn v1.0.78
[INFO] [stderr]   Downloaded libc v0.2.103
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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@sha256:4a844ea9eb2546a2d2c7022eacef16ef2e8229c7fbb2c7d4d55a9ceca922f72d" "/opt/rustwide/cargo-home/bin/cargo" "+39cb3386ddc6c71657418be28dbb3987eea4aa4b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c50fd77b0ccf765981a26856a4fab036ee72c84e4147462fc2f415c125e073b5
[INFO] running `Command { std: "docker" "start" "-a" "c50fd77b0ccf765981a26856a4fab036ee72c84e4147462fc2f415c125e073b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c50fd77b0ccf765981a26856a4fab036ee72c84e4147462fc2f415c125e073b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c50fd77b0ccf765981a26856a4fab036ee72c84e4147462fc2f415c125e073b5", kill_on_drop: false }`
[INFO] [stdout] c50fd77b0ccf765981a26856a4fab036ee72c84e4147462fc2f415c125e073b5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4a844ea9eb2546a2d2c7022eacef16ef2e8229c7fbb2c7d4d55a9ceca922f72d" "/opt/rustwide/cargo-home/bin/cargo" "+39cb3386ddc6c71657418be28dbb3987eea4aa4b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4b062d155689469bedc71bd08de7b71570a4498876b84914590ce56d590dffe6
[INFO] running `Command { std: "docker" "start" "-a" "4b062d155689469bedc71bd08de7b71570a4498876b84914590ce56d590dffe6", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.103
[INFO] [stderr]    Compiling semver v1.0.4
[INFO] [stderr]    Compiling crossbeam-utils v0.8.5
[INFO] [stderr]    Compiling serde v1.0.130
[INFO] [stderr]    Compiling memoffset v0.6.4
[INFO] [stderr]    Compiling memchr v2.4.1
[INFO] [stderr]    Compiling proc-macro2 v1.0.29
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.5
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling rayon-core v1.9.1
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]     Checking either v1.6.1
[INFO] [stderr]    Compiling syn v1.0.78
[INFO] [stderr]    Compiling serde_json v1.0.68
[INFO] [stderr]    Compiling rayon v1.5.1
[INFO] [stderr]     Checking plotters-backend v0.3.2
[INFO] [stderr]     Checking regex-automata v0.1.10
[INFO] [stderr]    Compiling serde_derive v1.0.130
[INFO] [stderr]     Checking unicode-width v0.1.9
[INFO] [stderr]     Checking itertools v0.10.1
[INFO] [stderr]     Checking plotters-svg v0.3.1
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking half v1.7.1
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]     Checking same-file v1.0.6
[INFO] [stderr]     Checking oorandom v11.1.3
[INFO] [stderr]     Checking rb_tree v0.5.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking walkdir v2.3.2
[INFO] [stderr]     Checking crossbeam-channel v0.5.1
[INFO] [stderr]    Compiling rustc_version v0.4.0
[INFO] [stdout] error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell`
[INFO] [stdout]    --> src/rbmap.rs:921:21
[INFO] [stdout]     |
[INFO] [stdout] 921 |                     &mut *(ptr as *mut Mapper<K, V>)
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>
[INFO] [stdout]     = note: even for types with interior mutability, the only legal way to obtain a mutable pointer from a shared reference is through `UnsafeCell::get`
[INFO] [stdout]     = note: `#[deny(invalid_reference_casting)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rb_tree` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "4b062d155689469bedc71bd08de7b71570a4498876b84914590ce56d590dffe6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4b062d155689469bedc71bd08de7b71570a4498876b84914590ce56d590dffe6", kill_on_drop: false }`
[INFO] [stdout] 4b062d155689469bedc71bd08de7b71570a4498876b84914590ce56d590dffe6
