[INFO] fetching crate mdbook 0.4.12...
[INFO] checking mdbook-0.4.12 against try#39e1293fce4b650061e85dda88aa428f726a8444 for pr-88041
[INFO] extracting crate mdbook 0.4.12 into /workspace/builds/worker-95/source
[INFO] validating manifest of crates.io crate mdbook 0.4.12 on toolchain 39e1293fce4b650061e85dda88aa428f726a8444
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mdbook 0.4.12
[INFO] finished tweaking crates.io crate mdbook 0.4.12
[INFO] tweaked toml for crates.io crate mdbook 0.4.12 written to /workspace/builds/worker-95/source/Cargo.toml
[INFO] crate crates.io crate mdbook 0.4.12 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "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 notify v4.0.16
[INFO] [stderr]   Downloaded futures-macro v0.3.14
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-95/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-95/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" "+39e1293fce4b650061e85dda88aa428f726a8444" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6505bbd3f26d84e161aebc3c8a947c4bd652b879110676bac4b9cf89da83e9fb
[INFO] running `Command { std: "docker" "start" "-a" "6505bbd3f26d84e161aebc3c8a947c4bd652b879110676bac4b9cf89da83e9fb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6505bbd3f26d84e161aebc3c8a947c4bd652b879110676bac4b9cf89da83e9fb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6505bbd3f26d84e161aebc3c8a947c4bd652b879110676bac4b9cf89da83e9fb", kill_on_drop: false }`
[INFO] [stdout] 6505bbd3f26d84e161aebc3c8a947c4bd652b879110676bac4b9cf89da83e9fb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-95/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-95/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" "+39e1293fce4b650061e85dda88aa428f726a8444" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f4ac1eb23dc297981785f788353a7737ad6c9027c87bee800470f1c2431a36ae
[INFO] running `Command { std: "docker" "start" "-a" "f4ac1eb23dc297981785f788353a7737ad6c9027c87bee800470f1c2431a36ae", 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" "f4ac1eb23dc297981785f788353a7737ad6c9027c87bee800470f1c2431a36ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f4ac1eb23dc297981785f788353a7737ad6c9027c87bee800470f1c2431a36ae", kill_on_drop: false }`
[INFO] [stdout] f4ac1eb23dc297981785f788353a7737ad6c9027c87bee800470f1c2431a36ae