[INFO] fetching crate backtrace 0.3.73...
[INFO] checking backtrace-0.3.73 against master#1f12b9b0fdbe735968ac002792a720f0ba4faca6 for crater-rollup-uwu
[INFO] extracting crate backtrace 0.3.73 into /workspace/builds/worker-4-tc1/source
[INFO] validating manifest of crates.io crate backtrace 0.3.73 on toolchain 1f12b9b0fdbe735968ac002792a720f0ba4faca6
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1f12b9b0fdbe735968ac002792a720f0ba4faca6" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate backtrace 0.3.73
[INFO] removed 0 missing examples
[INFO] removed 0 missing tests
[INFO] finished tweaking crates.io crate backtrace 0.3.73
[INFO] tweaked toml for crates.io crate backtrace 0.3.73 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate crates.io crate backtrace 0.3.73 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" "+1f12b9b0fdbe735968ac002792a720f0ba4faca6" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded unicode-ident v1.0.11
[INFO] [stderr]   Downloaded cpp_demangle v0.4.3
[INFO] [stderr]   Downloaded proc-macro2 v1.0.66
[INFO] [stderr]   Downloaded syn v2.0.29
[INFO] [stderr]   Downloaded object v0.36.0
[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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+1f12b9b0fdbe735968ac002792a720f0ba4faca6" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9ad257a2b48c5af4beecd9b90efb85bfee5c60f549d8f20a0fa82a53bdda1cd0
[INFO] running `Command { std: "docker" "start" "-a" "9ad257a2b48c5af4beecd9b90efb85bfee5c60f549d8f20a0fa82a53bdda1cd0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9ad257a2b48c5af4beecd9b90efb85bfee5c60f549d8f20a0fa82a53bdda1cd0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9ad257a2b48c5af4beecd9b90efb85bfee5c60f549d8f20a0fa82a53bdda1cd0", kill_on_drop: false }`
[INFO] [stdout] 9ad257a2b48c5af4beecd9b90efb85bfee5c60f549d8f20a0fa82a53bdda1cd0
[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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+1f12b9b0fdbe735968ac002792a720f0ba4faca6" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 09acf6f82b1e622918576e05ed30ced22dd13f402d1611ac35c2d3d4747f4b17
[INFO] running `Command { std: "docker" "start" "-a" "09acf6f82b1e622918576e05ed30ced22dd13f402d1611ac35c2d3d4747f4b17", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling libc v0.2.147
[INFO] [stderr]    Compiling cc v1.0.97
[INFO] [stderr]     Checking gimli v0.29.0
[INFO] [stderr]     Checking rustc-demangle v0.1.24
[INFO] [stderr]     Checking miniz_oxide v0.7.1
[INFO] [stderr]     Checking object v0.36.0
[INFO] [stderr]    Compiling backtrace v0.3.73 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking addr2line v0.22.0
[INFO] [stdout] warning: unused return value of `must_use` that must be used
[INFO] [stdout]   --> tests/concurrent-panics.rs:50:13
[INFO] [stdout]    |
[INFO] [stdout] 50 |             format!("{:?}", backtrace::Backtrace::new());
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this warning originates in the macro `format` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 5.65s
[INFO] running `Command { std: "docker" "inspect" "09acf6f82b1e622918576e05ed30ced22dd13f402d1611ac35c2d3d4747f4b17", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "09acf6f82b1e622918576e05ed30ced22dd13f402d1611ac35c2d3d4747f4b17", kill_on_drop: false }`
[INFO] [stdout] 09acf6f82b1e622918576e05ed30ced22dd13f402d1611ac35c2d3d4747f4b17