[INFO] fetching crate combinatorics 0.0.1...
[INFO] checking combinatorics-0.0.1 against try#07fecb9cf34c4979a772ba38c99d6d9144768413 for pr-87710
[INFO] extracting crate combinatorics 0.0.1 into /workspace/builds/worker-63/source
[INFO] validating manifest of crates.io crate combinatorics 0.0.1 on toolchain 07fecb9cf34c4979a772ba38c99d6d9144768413
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate combinatorics 0.0.1
[INFO] finished tweaking crates.io crate combinatorics 0.0.1
[INFO] tweaked toml for crates.io crate combinatorics 0.0.1 written to /workspace/builds/worker-63/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "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" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-63/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-63/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" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7df11c8141307ba0f0ca8396972c1425d8248170fc9e9af8a861710f52369b26
[INFO] running `Command { std: "docker" "start" "-a" "7df11c8141307ba0f0ca8396972c1425d8248170fc9e9af8a861710f52369b26", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7df11c8141307ba0f0ca8396972c1425d8248170fc9e9af8a861710f52369b26", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7df11c8141307ba0f0ca8396972c1425d8248170fc9e9af8a861710f52369b26", kill_on_drop: false }`
[INFO] [stdout] 7df11c8141307ba0f0ca8396972c1425d8248170fc9e9af8a861710f52369b26
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-63/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-63/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" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b970ae97c0c969541eac1b33a9ae534524b9abf316eaeae3066fa6e0d3377b1d
[INFO] running `Command { std: "docker" "start" "-a" "b970ae97c0c969541eac1b33a9ae534524b9abf316eaeae3066fa6e0d3377b1d", kill_on_drop: false }`
[INFO] [stderr]     Checking combinatorics v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0658]: use of unstable library feature 'rustc_private': this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via `Cargo.toml` instead?
[INFO] [stdout]   --> src/lib.rs:29:1
[INFO] [stdout]    |
[INFO] [stdout] 29 | extern crate libc;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #27812 <https://github.com/rust-lang/rust/issues/27812> for more information
[INFO] [stdout]    = help: add `#![feature(rustc_private)]` to the crate attributes to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: use of unstable library feature 'rustc_private': this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via `Cargo.toml` instead?
[INFO] [stdout]   --> src/lib.rs:29:1
[INFO] [stdout]    |
[INFO] [stdout] 29 | extern crate libc;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #27812 <https://github.com/rust-lang/rust/issues/27812> for more information
[INFO] [stdout]    = help: add `#![feature(rustc_private)]` to the crate attributes to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0658`.
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0658`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `combinatorics` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "b970ae97c0c969541eac1b33a9ae534524b9abf316eaeae3066fa6e0d3377b1d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b970ae97c0c969541eac1b33a9ae534524b9abf316eaeae3066fa6e0d3377b1d", kill_on_drop: false }`
[INFO] [stdout] b970ae97c0c969541eac1b33a9ae534524b9abf316eaeae3066fa6e0d3377b1d