[INFO] updating cached repository https://github.com/learn-you-a-rust/references
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 6ff4ef6f42c370e58278100c0a8e74b01e4b82a9
[INFO] testing learn-you-a-rust/references against try#03a1ea71b075ab964b5278bc6e74cd6c52c36ee0 for pr-74409
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flearn-you-a-rust%2Freferences" "/workspace/builds/worker-11/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/learn-you-a-rust/references on toolchain 03a1ea71b075ab964b5278bc6e74cd6c52c36ee0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/learn-you-a-rust/references
[INFO] finished tweaking git repo https://github.com/learn-you-a-rust/references
[INFO] tweaked toml for git repo https://github.com/learn-you-a-rust/references written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/learn-you-a-rust/references already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0f9e010944142f7126df1bbfdd57970dd49db3d62313030a95ce88efdbea3409
[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" "0f9e010944142f7126df1bbfdd57970dd49db3d62313030a95ce88efdbea3409", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0f9e010944142f7126df1bbfdd57970dd49db3d62313030a95ce88efdbea3409", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0f9e010944142f7126df1bbfdd57970dd49db3d62313030a95ce88efdbea3409", kill_on_drop: false }`
[INFO] [stdout] 0f9e010944142f7126df1bbfdd57970dd49db3d62313030a95ce88efdbea3409
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0a78b0f48be6b5f453005b173e6868c40138004af8713ec32d4061e41a1fa15c
[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" "0a78b0f48be6b5f453005b173e6868c40138004af8713ec32d4061e41a1fa15c", kill_on_drop: false }`
[INFO] [stderr]    Compiling references v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `s4`
[INFO] [stdout]   --> src/main.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let s4 = &s1;        // <-- if this ref exists, &mut s1 refs can't be used 
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s4`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/main.rs:31:13
[INFO] [stdout]    |
[INFO] [stdout] 31 |         let s2 = &mut s1;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `reference_to_nothing`
[INFO] [stdout]   --> src/main.rs:45:9
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let reference_to_nothing = no_dangle();
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_reference_to_nothing`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]   --> src/main.rs:65:11
[INFO] [stdout]    |
[INFO] [stdout] 65 | fn change(some_string: &String) {
[INFO] [stdout]    |           ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `change`
[INFO] [stdout]   --> src/main.rs:65:4
[INFO] [stdout]    |
[INFO] [stdout] 65 | fn change(some_string: &String) {
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.62s
[INFO] running `Command { std: "docker" "inspect" "0a78b0f48be6b5f453005b173e6868c40138004af8713ec32d4061e41a1fa15c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0a78b0f48be6b5f453005b173e6868c40138004af8713ec32d4061e41a1fa15c", kill_on_drop: false }`
[INFO] [stdout] 0a78b0f48be6b5f453005b173e6868c40138004af8713ec32d4061e41a1fa15c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ba1473b429cc69e723b9ff4a06704ad8fbfd66b6b4131bc8fa815220a74e16ac
[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" "ba1473b429cc69e723b9ff4a06704ad8fbfd66b6b4131bc8fa815220a74e16ac", kill_on_drop: false }`
[INFO] [stderr]    Compiling references v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `s4`
[INFO] [stdout]   --> src/main.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let s4 = &s1;        // <-- if this ref exists, &mut s1 refs can't be used 
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s4`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/main.rs:31:13
[INFO] [stdout]    |
[INFO] [stdout] 31 |         let s2 = &mut s1;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `reference_to_nothing`
[INFO] [stdout]   --> src/main.rs:45:9
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let reference_to_nothing = no_dangle();
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_reference_to_nothing`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]   --> src/main.rs:65:11
[INFO] [stdout]    |
[INFO] [stdout] 65 | fn change(some_string: &String) {
[INFO] [stdout]    |           ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `change`
[INFO] [stdout]   --> src/main.rs:65:4
[INFO] [stdout]    |
[INFO] [stdout] 65 | fn change(some_string: &String) {
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.47s
[INFO] running `Command { std: "docker" "inspect" "ba1473b429cc69e723b9ff4a06704ad8fbfd66b6b4131bc8fa815220a74e16ac", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ba1473b429cc69e723b9ff4a06704ad8fbfd66b6b4131bc8fa815220a74e16ac", kill_on_drop: false }`
[INFO] [stdout] ba1473b429cc69e723b9ff4a06704ad8fbfd66b6b4131bc8fa815220a74e16ac
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 88186139e39f14007f574f0fc91074b1a9988f606f17042f56c65af7f5d14292
[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" "88186139e39f14007f574f0fc91074b1a9988f606f17042f56c65af7f5d14292", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `s4`
[INFO] [stderr]   --> src/main.rs:19:9
[INFO] [stderr]    |
[INFO] [stderr] 19 |     let s4 = &s1;        // <-- if this ref exists, &mut s1 refs can't be used 
[INFO] [stderr]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s4`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s2`
[INFO] [stderr]   --> src/main.rs:31:13
[INFO] [stderr]    |
[INFO] [stderr] 31 |         let s2 = &mut s1;
[INFO] [stderr]    |             ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `reference_to_nothing`
[INFO] [stderr]   --> src/main.rs:45:9
[INFO] [stderr]    |
[INFO] [stderr] 45 |     let reference_to_nothing = no_dangle();
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_reference_to_nothing`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `some_string`
[INFO] [stderr]   --> src/main.rs:65:11
[INFO] [stderr]    |
[INFO] [stderr] 65 | fn change(some_string: &String) {
[INFO] [stderr]    |           ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `change`
[INFO] [stderr]   --> src/main.rs:65:4
[INFO] [stderr]    |
[INFO] [stderr] 65 | fn change(some_string: &String) {
[INFO] [stderr]    |    ^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 5 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.00s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/references-e8f7807ae4af5803
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "88186139e39f14007f574f0fc91074b1a9988f606f17042f56c65af7f5d14292", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "88186139e39f14007f574f0fc91074b1a9988f606f17042f56c65af7f5d14292", kill_on_drop: false }`
[INFO] [stdout] 88186139e39f14007f574f0fc91074b1a9988f606f17042f56c65af7f5d14292