[INFO] cloning repository https://github.com/tetuyoko/my-wordcount [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tetuyoko/my-wordcount" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount'... [INFO] [stderr] error: unable to create temporary file: No space left on device [INFO] [stderr] fatal: failed to write object [INFO] [stderr] fatal: unpack-objects failed [WARN] Retrying crate fetch in 3 seconds (attempt 1) [INFO] cloning repository https://github.com/tetuyoko/my-wordcount [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tetuyoko/my-wordcount" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount'... [INFO] [stderr] error: file write error: No space left on device [INFO] [stderr] fatal: unable to write loose object file [INFO] [stderr] fatal: unpack-objects failed [WARN] Retrying crate fetch in 3 seconds (attempt 2) [INFO] cloning repository https://github.com/tetuyoko/my-wordcount [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tetuyoko/my-wordcount" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount'... [INFO] [stderr] error: file write error: No space left on device [INFO] [stderr] fatal: unable to write loose object file [INFO] [stderr] fatal: unpack-objects failed [WARN] Retrying crate fetch in 3 seconds (attempt 3) [INFO] cloning repository https://github.com/tetuyoko/my-wordcount [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tetuyoko/my-wordcount" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount'... [INFO] [stderr] error: unable to create temporary file: No space left on device [INFO] [stderr] fatal: failed to write object [INFO] [stderr] fatal: unpack-objects failed [WARN] Retrying crate fetch in 3 seconds (attempt 4) [INFO] cloning repository https://github.com/tetuyoko/my-wordcount [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tetuyoko/my-wordcount" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount'... [INFO] [stderr] error: unable to create temporary file: No space left on device [INFO] [stderr] fatal: failed to write object [INFO] [stderr] fatal: unpack-objects failed [WARN] Retrying crate fetch in 3 seconds (attempt 5) [INFO] cloning repository https://github.com/tetuyoko/my-wordcount [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tetuyoko/my-wordcount" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount'... [INFO] [stderr] error: file write error: No space left on device [INFO] [stderr] fatal: unable to write loose object file [INFO] [stderr] fatal: unpack-objects failed [WARN] Retrying crate fetch in 3 seconds (attempt 6) [INFO] cloning repository https://github.com/tetuyoko/my-wordcount [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tetuyoko/my-wordcount" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount'... [INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount: No space left on device [WARN] Retrying crate fetch in 3 seconds (attempt 7) [INFO] cloning repository https://github.com/tetuyoko/my-wordcount [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tetuyoko/my-wordcount" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] 965d87b4353c51918d811fc5c0460c53f25ca1e1 [INFO] documenting tetuyoko/my-wordcount against master#ef324565d071c6d7e2477a195648549e33d6a465 for pr-121659-bump-pulldown-cmark [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/tetuyoko/my-wordcount on toolchain ef324565d071c6d7e2477a195648549e33d6a465 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ef324565d071c6d7e2477a195648549e33d6a465" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/tetuyoko/my-wordcount [INFO] finished tweaking git repo https://github.com/tetuyoko/my-wordcount [INFO] tweaked toml for git repo https://github.com/tetuyoko/my-wordcount written to /workspace/builds/worker-7-tc1/source/Cargo.toml [INFO] crate git repo https://github.com/tetuyoko/my-wordcount 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" "+ef324565d071c6d7e2477a195648549e33d6a465" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+ef324565d071c6d7e2477a195648549e33d6a465" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] a5f013410b020da05e90bd456dc2930f208f8ff5531c1d8310a12043e1272105 [INFO] running `Command { std: "docker" "start" "-a" "a5f013410b020da05e90bd456dc2930f208f8ff5531c1d8310a12043e1272105", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "a5f013410b020da05e90bd456dc2930f208f8ff5531c1d8310a12043e1272105", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "a5f013410b020da05e90bd456dc2930f208f8ff5531c1d8310a12043e1272105", kill_on_drop: false }` [INFO] [stdout] a5f013410b020da05e90bd456dc2930f208f8ff5531c1d8310a12043e1272105 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+ef324565d071c6d7e2477a195648549e33d6a465" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] 6bca22b23dbfb285f46e93fdef97da64d5428f8452d5118c253ed32227e13e59 [INFO] running `Command { std: "docker" "start" "-a" "6bca22b23dbfb285f46e93fdef97da64d5428f8452d5118c253ed32227e13e59", kill_on_drop: false }` [INFO] [stderr] error: failed to create directory `/opt/rustwide/target/debug/build/memchr-998d9cb3eac44f60/out` [INFO] [stderr] [INFO] [stderr] Caused by: [INFO] [stderr] No space left on device (os error 28) [INFO] running `Command { std: "docker" "inspect" "6bca22b23dbfb285f46e93fdef97da64d5428f8452d5118c253ed32227e13e59", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "6bca22b23dbfb285f46e93fdef97da64d5428f8452d5118c253ed32227e13e59", kill_on_drop: false }` [INFO] [stdout] 6bca22b23dbfb285f46e93fdef97da64d5428f8452d5118c253ed32227e13e59 [INFO] documenting tetuyoko/my-wordcount against try#223112bf1ca31911a6475910c77b36bfa127d5f8 for pr-121659-bump-pulldown-cmark [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/tetuyoko/my-wordcount on toolchain 223112bf1ca31911a6475910c77b36bfa127d5f8 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+223112bf1ca31911a6475910c77b36bfa127d5f8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/tetuyoko/my-wordcount [INFO] finished tweaking git repo https://github.com/tetuyoko/my-wordcount [INFO] tweaked toml for git repo https://github.com/tetuyoko/my-wordcount written to /workspace/builds/worker-7-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/tetuyoko/my-wordcount 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" "+223112bf1ca31911a6475910c77b36bfa127d5f8" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+223112bf1ca31911a6475910c77b36bfa127d5f8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stderr] Error response from daemon: mkdir /var/lib/docker/containers/a44624deab00266a6b5ed0a7a67116ed8c7dbe151ccaff7e279323bddddb3b38/checkpoints: no space left on device [INFO] documenting tetuyoko/my-wordcount against try#223112bf1ca31911a6475910c77b36bfa127d5f8 for pr-121659-bump-pulldown-cmark [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/tetuyoko/my-wordcount on toolchain 223112bf1ca31911a6475910c77b36bfa127d5f8 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+223112bf1ca31911a6475910c77b36bfa127d5f8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/tetuyoko/my-wordcount [INFO] finished tweaking git repo https://github.com/tetuyoko/my-wordcount [INFO] tweaked toml for git repo https://github.com/tetuyoko/my-wordcount written to /workspace/builds/worker-7-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/tetuyoko/my-wordcount 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" "+223112bf1ca31911a6475910c77b36bfa127d5f8" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+223112bf1ca31911a6475910c77b36bfa127d5f8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stderr] Error response from daemon: write /var/lib/docker/image/overlay2/layerdb/mounts/cb1a1e97580616ff4e11a3efb036b42bd1ad9e2ed18400a472d1d7356ce4d368/parent: no space left on device [INFO] documenting tetuyoko/my-wordcount against try#223112bf1ca31911a6475910c77b36bfa127d5f8 for pr-121659-bump-pulldown-cmark [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/tetuyoko/my-wordcount on toolchain 223112bf1ca31911a6475910c77b36bfa127d5f8 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+223112bf1ca31911a6475910c77b36bfa127d5f8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/tetuyoko/my-wordcount [INFO] finished tweaking git repo https://github.com/tetuyoko/my-wordcount [INFO] tweaked toml for git repo https://github.com/tetuyoko/my-wordcount written to /workspace/builds/worker-7-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/tetuyoko/my-wordcount 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" "+223112bf1ca31911a6475910c77b36bfa127d5f8" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+223112bf1ca31911a6475910c77b36bfa127d5f8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stderr] Error response from daemon: mkdir /var/lib/docker/overlay2/5f3bf0b9ebffb2dd7a3b2a7d0e8b245e278a2d02f09e83d471a77cce01e3626a-init: no space left on device [INFO] documenting tetuyoko/my-wordcount against try#223112bf1ca31911a6475910c77b36bfa127d5f8 for pr-121659-bump-pulldown-cmark [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'... [INFO] [stderr] done. [INFO] [stderr] fatal: unable to write new index file [INFO] [stderr] warning: Clone succeeded, but checkout failed. [INFO] [stderr] You can inspect what was checked out with 'git status' [INFO] [stderr] and retry with 'git restore --source=HEAD :/' [INFO] [stderr] [INFO] documenting tetuyoko/my-wordcount against try#223112bf1ca31911a6475910c77b36bfa127d5f8 for pr-121659-bump-pulldown-cmark [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftetuyoko%2Fmy-wordcount" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'... [INFO] [stderr] done. [INFO] [stderr] fatal: unable to write new index file [INFO] [stderr] warning: Clone succeeded, but checkout failed. [INFO] [stderr] You can inspect what was checked out with 'git status' [INFO] [stderr] and retry with 'git restore --source=HEAD :/' [INFO] [stderr] [ERROR] this task or one of its parent failed! [ERROR] failed to checkout https://github.com/tetuyoko/my-wordcount [ERROR] caused by: command failed: exit status: 128 [ERROR] note: run with `RUST_BACKTRACE=1` to display a backtrace.