[INFO] crate smoltcp 0.5.0 is already in cache
[INFO] extracting crate smoltcp 0.5.0 into work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/reg/smoltcp/0.5.0
[INFO] extracting crate smoltcp 0.5.0 into work/ex/pr-60914/sources/try#f45cc3094ee337acd688771b9234318046b0572d/reg/smoltcp/0.5.0
[INFO] validating manifest of smoltcp-0.5.0 on toolchain master#39401465da4ce27aeeb2c2a26133ac35c63aa515
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of smoltcp-0.5.0 on toolchain try#f45cc3094ee337acd688771b9234318046b0572d
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+f45cc3094ee337acd688771b9234318046b0572d-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing smoltcp-0.5.0
[INFO] removed 8 missing examples
[INFO] finished frobbing smoltcp-0.5.0
[INFO] frobbed toml for smoltcp-0.5.0 written to work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/reg/smoltcp/0.5.0/Cargo.toml
[INFO] started frobbing smoltcp-0.5.0
[INFO] removed 8 missing examples
[INFO] finished frobbing smoltcp-0.5.0
[INFO] frobbed toml for smoltcp-0.5.0 written to work/ex/pr-60914/sources/try#f45cc3094ee337acd688771b9234318046b0572d/reg/smoltcp/0.5.0/Cargo.toml
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+f45cc3094ee337acd688771b9234318046b0572d-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+f45cc3094ee337acd688771b9234318046b0572d-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking smoltcp-0.5.0 against master#39401465da4ce27aeeb2c2a26133ac35c63aa515 for pr-60914
[INFO] running `"docker" "create" "-v" "/mnt/crater-raid/crater/work/local/target-dirs/pr-60914/worker-4/master#39401465da4ce27aeeb2c2a26133ac35c63aa515:/opt/crater/target:rw,Z" "-v" "/mnt/crater-raid/crater/work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/reg/smoltcp/0.5.0:/opt/crater/workdir:ro,Z" "-v" "/mnt/crater-raid/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/crater-raid/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 2c1853c6095091a70fe107ffe978f084f5cc89affe77f17e01795b88f3784a2b
[INFO] running `"docker" "start" "-a" "2c1853c6095091a70fe107ffe978f084f5cc89affe77f17e01795b88f3784a2b"`
[INFO] [stderr]     Checking managed v0.7.1
[INFO] [stderr]     Checking bitflags v1.0.4
[INFO] [stderr]     Checking smoltcp v0.5.0 (/opt/crater/workdir)
[INFO] [stderr] error: variable does not need to be mutable
[INFO] [stderr]    --> src/socket/raw.rs:177:25
[INFO] [stderr]     |
[INFO] [stderr] 177 |                     let mut packet = Ipv6Packet::new_checked(buffer.as_mut())?;
[INFO] [stderr]     |                         ----^^^^^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr] note: lint level defined here
[INFO] [stderr]    --> src/lib.rs:4:71
[INFO] [stderr]     |
[INFO] [stderr] 4   | #![cfg_attr(any(feature = "proto-ipv4", feature = "proto-ipv6"), deny(unused))]
[INFO] [stderr]     |                                                                       ^^^^^^
[INFO] [stderr]     = note: #[deny(unused_mut)] implied by #[deny(unused)]
[INFO] [stderr] 
[INFO] [stderr] warning[E0713]: borrow may still be in use when destructor runs
[INFO] [stderr]   --> src/socket/ref_.rs:61:9
[INFO] [stderr]    |
[INFO] [stderr] 39 | impl<'a, T: Session + 'a> Ref<'a, T> {
[INFO] [stderr]    |      -- lifetime `'a` defined here
[INFO] [stderr] ...
[INFO] [stderr] 61 |         ref_.socket
[INFO] [stderr]    |         ^^^^^^^^^^^ returning this value requires that `*ref_.socket` is borrowed for `'a`
[INFO] [stderr] 62 |     }
[INFO] [stderr]    |     - here, drop of `ref_` needs exclusive access to `*ref_.socket`, because the type `socket::ref_::Ref<'_, T>` implements the `Drop` trait
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this error has been downgraded to a warning for backwards compatibility with previous releases
[INFO] [stderr]    = warning: this represents potential undefined behavior in your code and this warning will become a hard error in the future
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0713`.
[INFO] [stderr] error: Could not compile `smoltcp`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: variable does not need to be mutable
[INFO] [stderr]    --> src/socket/raw.rs:177:25
[INFO] [stderr]     |
[INFO] [stderr] 177 |                     let mut packet = Ipv6Packet::new_checked(buffer.as_mut())?;
[INFO] [stderr]     |                         ----^^^^^^
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr] note: lint level defined here
[INFO] [stderr]    --> src/lib.rs:4:71
[INFO] [stderr]     |
[INFO] [stderr] 4   | #![cfg_attr(any(feature = "proto-ipv4", feature = "proto-ipv6"), deny(unused))]
[INFO] [stderr]     |                                                                       ^^^^^^
[INFO] [stderr]     = note: #[deny(unused_mut)] implied by #[deny(unused)]
[INFO] [stderr] 
[INFO] [stderr] warning[E0713]: borrow may still be in use when destructor runs
[INFO] [stderr]   --> src/socket/ref_.rs:61:9
[INFO] [stderr]    |
[INFO] [stderr] 39 | impl<'a, T: Session + 'a> Ref<'a, T> {
[INFO] [stderr]    |      -- lifetime `'a` defined here
[INFO] [stderr] ...
[INFO] [stderr] 61 |         ref_.socket
[INFO] [stderr]    |         ^^^^^^^^^^^ returning this value requires that `*ref_.socket` is borrowed for `'a`
[INFO] [stderr] 62 |     }
[INFO] [stderr]    |     - here, drop of `ref_` needs exclusive access to `*ref_.socket`, because the type `socket::ref_::Ref<'_, T>` implements the `Drop` trait
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this error has been downgraded to a warning for backwards compatibility with previous releases
[INFO] [stderr]    = warning: this represents potential undefined behavior in your code and this warning will become a hard error in the future
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0713`.
[INFO] [stderr] error: Could not compile `smoltcp`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "2c1853c6095091a70fe107ffe978f084f5cc89affe77f17e01795b88f3784a2b"`
[INFO] running `"docker" "rm" "-f" "2c1853c6095091a70fe107ffe978f084f5cc89affe77f17e01795b88f3784a2b"`
[INFO] [stdout] 2c1853c6095091a70fe107ffe978f084f5cc89affe77f17e01795b88f3784a2b