[INFO] cloning repository https://github.com/kurnev/auction [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/kurnev/auction" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkurnev%2Fauction", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkurnev%2Fauction'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] 60ef861fe2f4b15950905a9eb8743d180f7465e9 [INFO] checking kurnev/auction against master#74c3f5a146860c94ff4d179fc3bfa34f879adf41 for pr-120248 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkurnev%2Fauction" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/kurnev/auction on toolchain 74c3f5a146860c94ff4d179fc3bfa34f879adf41 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+74c3f5a146860c94ff4d179fc3bfa34f879adf41" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/kurnev/auction [INFO] finished tweaking git repo https://github.com/kurnev/auction [INFO] tweaked toml for git repo https://github.com/kurnev/auction written to /workspace/builds/worker-0-tc1/source/Cargo.toml [INFO] crate git repo https://github.com/kurnev/auction 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" "+74c3f5a146860c94ff4d179fc3bfa34f879adf41" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+74c3f5a146860c94ff4d179fc3bfa34f879adf41" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 82449feb8e6863c1391bf53c7e364f44f2e77fc020e4315b960f0040ea0fbea4 [INFO] running `Command { std: "docker" "start" "-a" "82449feb8e6863c1391bf53c7e364f44f2e77fc020e4315b960f0040ea0fbea4", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "82449feb8e6863c1391bf53c7e364f44f2e77fc020e4315b960f0040ea0fbea4", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "82449feb8e6863c1391bf53c7e364f44f2e77fc020e4315b960f0040ea0fbea4", kill_on_drop: false }` [INFO] [stdout] 82449feb8e6863c1391bf53c7e364f44f2e77fc020e4315b960f0040ea0fbea4 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+74c3f5a146860c94ff4d179fc3bfa34f879adf41" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] efe355ec144d277eeb013d44eb007d8119101b7cb7eeec9568b8f5811a60bf11 [INFO] running `Command { std: "docker" "start" "-a" "efe355ec144d277eeb013d44eb007d8119101b7cb7eeec9568b8f5811a60bf11", kill_on_drop: false }` [INFO] [stderr] error: failed to create directory `/opt/rustwide/target/debug` [INFO] [stderr] [INFO] [stderr] Caused by: [INFO] [stderr] No space left on device (os error 28) [INFO] running `Command { std: "docker" "inspect" "efe355ec144d277eeb013d44eb007d8119101b7cb7eeec9568b8f5811a60bf11", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "efe355ec144d277eeb013d44eb007d8119101b7cb7eeec9568b8f5811a60bf11", kill_on_drop: false }` [INFO] [stdout] efe355ec144d277eeb013d44eb007d8119101b7cb7eeec9568b8f5811a60bf11 [INFO] checking kurnev/auction against try#13cae6066db2d5e6c9bb508caceec8d34ca49980 for pr-120248 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkurnev%2Fauction" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/kurnev/auction on toolchain 13cae6066db2d5e6c9bb508caceec8d34ca49980 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/kurnev/auction [INFO] finished tweaking git repo https://github.com/kurnev/auction [INFO] tweaked toml for git repo https://github.com/kurnev/auction written to /workspace/builds/worker-0-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/kurnev/auction 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" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 22c2e0f1752cf442c6fec414806dc29f12789174cfd55839fa0214fe9e9a44fd [INFO] running `Command { std: "docker" "start" "-a" "22c2e0f1752cf442c6fec414806dc29f12789174cfd55839fa0214fe9e9a44fd", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "22c2e0f1752cf442c6fec414806dc29f12789174cfd55839fa0214fe9e9a44fd", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "22c2e0f1752cf442c6fec414806dc29f12789174cfd55839fa0214fe9e9a44fd", kill_on_drop: false }` [INFO] [stdout] 22c2e0f1752cf442c6fec414806dc29f12789174cfd55839fa0214fe9e9a44fd [INFO] checking kurnev/auction against try#13cae6066db2d5e6c9bb508caceec8d34ca49980 for pr-120248 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkurnev%2Fauction" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/kurnev/auction on toolchain 13cae6066db2d5e6c9bb508caceec8d34ca49980 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/kurnev/auction [INFO] finished tweaking git repo https://github.com/kurnev/auction [INFO] tweaked toml for git repo https://github.com/kurnev/auction written to /workspace/builds/worker-0-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/kurnev/auction 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" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] da8086ee49f7883733d6abf60f81615ccf113512d090f51136b89a56f8624e93 [INFO] running `Command { std: "docker" "start" "-a" "da8086ee49f7883733d6abf60f81615ccf113512d090f51136b89a56f8624e93", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "da8086ee49f7883733d6abf60f81615ccf113512d090f51136b89a56f8624e93", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "da8086ee49f7883733d6abf60f81615ccf113512d090f51136b89a56f8624e93", kill_on_drop: false }` [INFO] [stdout] da8086ee49f7883733d6abf60f81615ccf113512d090f51136b89a56f8624e93 [INFO] checking kurnev/auction against try#13cae6066db2d5e6c9bb508caceec8d34ca49980 for pr-120248 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkurnev%2Fauction" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/kurnev/auction on toolchain 13cae6066db2d5e6c9bb508caceec8d34ca49980 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/kurnev/auction [INFO] finished tweaking git repo https://github.com/kurnev/auction [INFO] tweaked toml for git repo https://github.com/kurnev/auction written to /workspace/builds/worker-0-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/kurnev/auction 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" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 7863f1463452f14760a0fd9b220d4f750f14e079c30b319715d70b1abad5ce37 [INFO] running `Command { std: "docker" "start" "-a" "7863f1463452f14760a0fd9b220d4f750f14e079c30b319715d70b1abad5ce37", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "7863f1463452f14760a0fd9b220d4f750f14e079c30b319715d70b1abad5ce37", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "7863f1463452f14760a0fd9b220d4f750f14e079c30b319715d70b1abad5ce37", kill_on_drop: false }` [INFO] [stdout] 7863f1463452f14760a0fd9b220d4f750f14e079c30b319715d70b1abad5ce37 [INFO] checking kurnev/auction against try#13cae6066db2d5e6c9bb508caceec8d34ca49980 for pr-120248 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkurnev%2Fauction" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/kurnev/auction on toolchain 13cae6066db2d5e6c9bb508caceec8d34ca49980 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/kurnev/auction [INFO] finished tweaking git repo https://github.com/kurnev/auction [INFO] tweaked toml for git repo https://github.com/kurnev/auction written to /workspace/builds/worker-0-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/kurnev/auction 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" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stderr] Error response from daemon: mkdir /var/lib/docker/overlay2/e0e10074d3354618634c298d88434e2b103e61f7f57f720783b68b2d7f3bba67/merged/opt/rustwide/workdir: no space left on device [INFO] checking kurnev/auction against try#13cae6066db2d5e6c9bb508caceec8d34ca49980 for pr-120248 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkurnev%2Fauction" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/kurnev/auction on toolchain 13cae6066db2d5e6c9bb508caceec8d34ca49980 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/kurnev/auction [INFO] finished tweaking git repo https://github.com/kurnev/auction [INFO] tweaked toml for git repo https://github.com/kurnev/auction written to /workspace/builds/worker-0-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/kurnev/auction 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" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+13cae6066db2d5e6c9bb508caceec8d34ca49980" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stderr] Error response from daemon: mkdir /var/lib/docker/overlay2/5c4c2b57d30ba2618f9ef4103bf401335d04409f4a1d16c2bcdf7650f5d54276/merged/opt/rustwide: 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.