[INFO] cloning repository https://github.com/llamicron/lab_grader
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/llamicron/lab_grader" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fllamicron%2Flab_grader", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fllamicron%2Flab_grader'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b6ed054bca8d3f20efc7ed995e23197ee089e6eb
[INFO] checking llamicron/lab_grader against master#8007b506ac5da629f223b755f5a5391edd5f6d01 for pr-88041
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fllamicron%2Flab_grader" "/workspace/builds/worker-52/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-52/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/llamicron/lab_grader on toolchain 8007b506ac5da629f223b755f5a5391edd5f6d01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/llamicron/lab_grader
[INFO] finished tweaking git repo https://github.com/llamicron/lab_grader
[INFO] tweaked toml for git repo https://github.com/llamicron/lab_grader written to /workspace/builds/worker-52/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded paris v1.5.7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-52/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-52/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 83cfced841c3fc1852a40959cc4fbca0044a2f73b32fd90b4a3e720056eba5bf
[INFO] running `Command { std: "docker" "start" "-a" "83cfced841c3fc1852a40959cc4fbca0044a2f73b32fd90b4a3e720056eba5bf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "83cfced841c3fc1852a40959cc4fbca0044a2f73b32fd90b4a3e720056eba5bf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "83cfced841c3fc1852a40959cc4fbca0044a2f73b32fd90b4a3e720056eba5bf", kill_on_drop: false }`
[INFO] [stdout] 83cfced841c3fc1852a40959cc4fbca0044a2f73b32fd90b4a3e720056eba5bf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-52/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-52/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" "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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7798af4fe43697d3e7a5c5f4dff128e0f99d581b88d5296b5e9686cebf078989
[INFO] running `Command { std: "docker" "start" "-a" "7798af4fe43697d3e7a5c5f4dff128e0f99d581b88d5296b5e9686cebf078989", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] error: failed to create jobserver
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   failed to increase jobserver pipe capacity from 4096 to 8192; jobserver otherwise might deadlock
[INFO] running `Command { std: "docker" "inspect" "7798af4fe43697d3e7a5c5f4dff128e0f99d581b88d5296b5e9686cebf078989", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7798af4fe43697d3e7a5c5f4dff128e0f99d581b88d5296b5e9686cebf078989", kill_on_drop: false }`
[INFO] [stdout] 7798af4fe43697d3e7a5c5f4dff128e0f99d581b88d5296b5e9686cebf078989