[INFO] fetching crate discard 1.0.4...
[INFO] extracting crate discard 1.0.4 into work/ex/pr-58899/sources/master#c0086b9e8972fef9fd4af24bae20d45021ed06c6/reg/discard/1.0.4
[INFO] extracting crate discard 1.0.4 into work/ex/pr-58899/sources/try#290ac7b29f41ff9fa5232f9a1116ea71a3501063/reg/discard/1.0.4
[INFO] validating manifest of discard-1.0.4 on toolchain master#c0086b9e8972fef9fd4af24bae20d45021ed06c6
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c0086b9e8972fef9fd4af24bae20d45021ed06c6-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of discard-1.0.4 on toolchain try#290ac7b29f41ff9fa5232f9a1116ea71a3501063
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+290ac7b29f41ff9fa5232f9a1116ea71a3501063-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing discard-1.0.4
[INFO] finished frobbing discard-1.0.4
[INFO] frobbed toml for discard-1.0.4 written to work/ex/pr-58899/sources/master#c0086b9e8972fef9fd4af24bae20d45021ed06c6/reg/discard/1.0.4/Cargo.toml
[INFO] started frobbing discard-1.0.4
[INFO] finished frobbing discard-1.0.4
[INFO] frobbed toml for discard-1.0.4 written to work/ex/pr-58899/sources/try#290ac7b29f41ff9fa5232f9a1116ea71a3501063/reg/discard/1.0.4/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c0086b9e8972fef9fd4af24bae20d45021ed06c6-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+290ac7b29f41ff9fa5232f9a1116ea71a3501063-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c0086b9e8972fef9fd4af24bae20d45021ed06c6-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+290ac7b29f41ff9fa5232f9a1116ea71a3501063-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking discard-1.0.4 against master#c0086b9e8972fef9fd4af24bae20d45021ed06c6 for pr-58899
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-58899/worker-3/master#c0086b9e8972fef9fd4af24bae20d45021ed06c6:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-58899/sources/master#c0086b9e8972fef9fd4af24bae20d45021ed06c6/reg/discard/1.0.4:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/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" "+c0086b9e8972fef9fd4af24bae20d45021ed06c6-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 2abef252120637369340a2c4b263b5237f8835704d37380d245755bee1ec3c5e
[INFO] running `"docker" "start" "-a" "2abef252120637369340a2c4b263b5237f8835704d37380d245755bee1ec3c5e"`
[INFO] [stderr]     Checking discard v1.0.4 (/opt/crater/workdir)
[INFO] [stderr] warning: unused `DiscardOnDrop` that must be used
[INFO] [stderr]    --> src/lib.rs:261:9
[INFO] [stderr]     |
[INFO] [stderr] 261 |         DiscardOnDrop::new(Foo::new());
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_must_use)] on by default
[INFO] [stderr]     = note: 
[INFO] [stderr]             The DiscardOnDrop is unused, which causes it to be immediately discarded.
[INFO] [stderr]             You probably don't want that to happen.
[INFO] [stderr]             
[INFO] [stderr]             How to fix this:
[INFO] [stderr]             
[INFO] [stderr]               * Store the DiscardOnDrop in a variable or data structure.
[INFO] [stderr]             
[INFO] [stderr]               * Or use the DiscardOnDrop::leak function which will cause it to not be
[INFO] [stderr]                 discarded (this *will* leak memory!).
[INFO] [stderr]             
[INFO] [stderr]             See the DiscardOnDrop documentation for more details.
[INFO] [stderr] 
[INFO] [stderr] warning: unused `DiscardOnDrop` that must be used
[INFO] [stderr]    --> src/lib.rs:262:9
[INFO] [stderr]     |
[INFO] [stderr] 262 |         DiscardOnDrop::new(Foo::new());
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: 
[INFO] [stderr]             The DiscardOnDrop is unused, which causes it to be immediately discarded.
[INFO] [stderr]             You probably don't want that to happen.
[INFO] [stderr]             
[INFO] [stderr]             How to fix this:
[INFO] [stderr]             
[INFO] [stderr]               * Store the DiscardOnDrop in a variable or data structure.
[INFO] [stderr]             
[INFO] [stderr]               * Or use the DiscardOnDrop::leak function which will cause it to not be
[INFO] [stderr]                 discarded (this *will* leak memory!).
[INFO] [stderr]             
[INFO] [stderr]             See the DiscardOnDrop documentation for more details.
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.53s
[INFO] running `"docker" "inspect" "2abef252120637369340a2c4b263b5237f8835704d37380d245755bee1ec3c5e"`
[INFO] running `"docker" "rm" "-f" "2abef252120637369340a2c4b263b5237f8835704d37380d245755bee1ec3c5e"`
[INFO] [stdout] 2abef252120637369340a2c4b263b5237f8835704d37380d245755bee1ec3c5e