[INFO] cloning repository https://github.com/vrmiguel/tson [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/vrmiguel/tson" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvrmiguel%2Ftson", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvrmiguel%2Ftson'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] 7803ae0668ebd4b497a8c5841067fe6e65b5ba5a [INFO] testing vrmiguel/tson against master#1ddedbaa5919b7b3e70d984660e21e844c615c97 for pr-128400 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvrmiguel%2Ftson" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/vrmiguel/tson on toolchain 1ddedbaa5919b7b3e70d984660e21e844c615c97 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1ddedbaa5919b7b3e70d984660e21e844c615c97" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/vrmiguel/tson [INFO] finished tweaking git repo https://github.com/vrmiguel/tson [INFO] tweaked toml for git repo https://github.com/vrmiguel/tson written to /workspace/builds/worker-2-tc1/source/Cargo.toml [INFO] crate git repo https://github.com/vrmiguel/tson 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" "+1ddedbaa5919b7b3e70d984660e21e844c615c97" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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" "+1ddedbaa5919b7b3e70d984660e21e844c615c97" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 467a03bc291c52ccb15101c660bb7524d88095b64627e8e242bb8be134954f34 [INFO] running `Command { std: "docker" "start" "-a" "467a03bc291c52ccb15101c660bb7524d88095b64627e8e242bb8be134954f34", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "467a03bc291c52ccb15101c660bb7524d88095b64627e8e242bb8be134954f34", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "467a03bc291c52ccb15101c660bb7524d88095b64627e8e242bb8be134954f34", kill_on_drop: false }` [INFO] [stdout] 467a03bc291c52ccb15101c660bb7524d88095b64627e8e242bb8be134954f34 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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" "+1ddedbaa5919b7b3e70d984660e21e844c615c97" "build" "--frozen" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] 1da60112e7254ec8e3b8af006271f38236409f39bec7c8db88619dbf61d85648 [INFO] running `Command { std: "docker" "start" "-a" "1da60112e7254ec8e3b8af006271f38236409f39bec7c8db88619dbf61d85648", kill_on_drop: false }` [INFO] [stderr] Compiling memchr v2.5.0 [INFO] [stderr] Compiling minimal-lexical v0.2.1 [INFO] [stderr] Compiling nom v7.1.1 [INFO] [stderr] rustc-LLVM ERROR: IO failure on output stream: No space left on device [INFO] [stderr] error: could not compile `memchr` (lib) [INFO] [stderr] warning: build failed, waiting for other jobs to finish... [INFO] [stdout] error: error writing dependencies to `/opt/rustwide/target/debug/deps/nom-6fcef2d36f2c1659.d`: No space left on device (os error 28) [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] error: could not compile `nom` (lib) due to 1 previous error [INFO] running `Command { std: "docker" "inspect" "1da60112e7254ec8e3b8af006271f38236409f39bec7c8db88619dbf61d85648", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "1da60112e7254ec8e3b8af006271f38236409f39bec7c8db88619dbf61d85648", kill_on_drop: false }` [INFO] [stdout] 1da60112e7254ec8e3b8af006271f38236409f39bec7c8db88619dbf61d85648 [INFO] testing vrmiguel/tson against try#33f1d8bb92813a1bfc23c093c9f443ab09290307 for pr-128400 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvrmiguel%2Ftson" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/vrmiguel/tson on toolchain 33f1d8bb92813a1bfc23c093c9f443ab09290307 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/vrmiguel/tson [INFO] finished tweaking git repo https://github.com/vrmiguel/tson [INFO] tweaked toml for git repo https://github.com/vrmiguel/tson written to /workspace/builds/worker-2-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/vrmiguel/tson 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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 6d757f8bacbd696ccdf4802a19b8fa68ea982027b4e636226f26a61c0fd341b6 [INFO] running `Command { std: "docker" "start" "-a" "6d757f8bacbd696ccdf4802a19b8fa68ea982027b4e636226f26a61c0fd341b6", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "6d757f8bacbd696ccdf4802a19b8fa68ea982027b4e636226f26a61c0fd341b6", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "6d757f8bacbd696ccdf4802a19b8fa68ea982027b4e636226f26a61c0fd341b6", kill_on_drop: false }` [INFO] [stdout] 6d757f8bacbd696ccdf4802a19b8fa68ea982027b4e636226f26a61c0fd341b6 [INFO] testing vrmiguel/tson against try#33f1d8bb92813a1bfc23c093c9f443ab09290307 for pr-128400 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvrmiguel%2Ftson" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/vrmiguel/tson on toolchain 33f1d8bb92813a1bfc23c093c9f443ab09290307 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/vrmiguel/tson [INFO] finished tweaking git repo https://github.com/vrmiguel/tson [INFO] tweaked toml for git repo https://github.com/vrmiguel/tson written to /workspace/builds/worker-2-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/vrmiguel/tson 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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 2fe7f3f044248538782fc90550dc711cdf6f49196b38dbac07a59d37642389a1 [INFO] running `Command { std: "docker" "start" "-a" "2fe7f3f044248538782fc90550dc711cdf6f49196b38dbac07a59d37642389a1", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "2fe7f3f044248538782fc90550dc711cdf6f49196b38dbac07a59d37642389a1", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "2fe7f3f044248538782fc90550dc711cdf6f49196b38dbac07a59d37642389a1", kill_on_drop: false }` [INFO] [stdout] 2fe7f3f044248538782fc90550dc711cdf6f49196b38dbac07a59d37642389a1 [INFO] testing vrmiguel/tson against try#33f1d8bb92813a1bfc23c093c9f443ab09290307 for pr-128400 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvrmiguel%2Ftson" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/vrmiguel/tson on toolchain 33f1d8bb92813a1bfc23c093c9f443ab09290307 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/vrmiguel/tson [INFO] finished tweaking git repo https://github.com/vrmiguel/tson [INFO] tweaked toml for git repo https://github.com/vrmiguel/tson written to /workspace/builds/worker-2-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/vrmiguel/tson 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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stderr] Error response from daemon: mkdir /var/lib/docker/overlay2/44f753af4e2618ba9eb2d5bcf92a1c4fce4a0a69740dba2a4db3c1e162faf3a7/merged/opt/rustwide: no space left on device [INFO] testing vrmiguel/tson against try#33f1d8bb92813a1bfc23c093c9f443ab09290307 for pr-128400 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvrmiguel%2Ftson" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/vrmiguel/tson on toolchain 33f1d8bb92813a1bfc23c093c9f443ab09290307 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/vrmiguel/tson [INFO] finished tweaking git repo https://github.com/vrmiguel/tson [INFO] tweaked toml for git repo https://github.com/vrmiguel/tson written to /workspace/builds/worker-2-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/vrmiguel/tson 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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stderr] Error response from daemon: chown /var/lib/docker/overlay2/217d6b89d1ff58ebad8d095d2580125bed2e6d889714a21f40f0722d3b05cf05/work/work: no such file or directory [INFO] testing vrmiguel/tson against try#33f1d8bb92813a1bfc23c093c9f443ab09290307 for pr-128400 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvrmiguel%2Ftson" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/vrmiguel/tson on toolchain 33f1d8bb92813a1bfc23c093c9f443ab09290307 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/vrmiguel/tson [INFO] finished tweaking git repo https://github.com/vrmiguel/tson [INFO] tweaked toml for git repo https://github.com/vrmiguel/tson written to /workspace/builds/worker-2-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/vrmiguel/tson 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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "+33f1d8bb92813a1bfc23c093c9f443ab09290307" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stderr] Error response from daemon: mkdir /var/lib/docker/overlay2/f088ae8d9e003d62a131e4dff385453fe2c3cb3e29c4f55ed73580c646934f25/merged: no space left on device [ERROR] this task or one of its parent failed! [ERROR] command failed: exit status: 1 [ERROR] note: run with `RUST_BACKTRACE=1` to display a backtrace.