[INFO] cloning repository https://github.com/Michael-F-Bryan/mdbook-linkcheck
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Michael-F-Bryan/mdbook-linkcheck" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMichael-F-Bryan%2Fmdbook-linkcheck", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMichael-F-Bryan%2Fmdbook-linkcheck'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] bffff60e6de6f755fab9dfd6ecc3f6cf872c633d
[INFO] checking Michael-F-Bryan/mdbook-linkcheck against master#506512391b1a75ae450d36c9420978402a91abcc for pr-125384
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMichael-F-Bryan%2Fmdbook-linkcheck" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Michael-F-Bryan/mdbook-linkcheck on toolchain 506512391b1a75ae450d36c9420978402a91abcc
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+506512391b1a75ae450d36c9420978402a91abcc" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-6-tc1/source/.cargo/config
[INFO] started tweaking git repo https://github.com/Michael-F-Bryan/mdbook-linkcheck
[INFO] finished tweaking git repo https://github.com/Michael-F-Bryan/mdbook-linkcheck
[INFO] tweaked toml for git repo https://github.com/Michael-F-Bryan/mdbook-linkcheck written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/Michael-F-Bryan/mdbook-linkcheck 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" "+506512391b1a75ae450d36c9420978402a91abcc" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded build-info v0.0.21
[INFO] [stderr]   Downloaded linkify v0.7.0
[INFO] [stderr]   Downloaded build-info-build v0.0.21
[INFO] [stderr]   Downloaded linkcheck v0.4.1
[INFO] [stderr]   Downloaded format-buf v1.0.0
[INFO] [stderr]   Downloaded build-info-common v0.0.21
[INFO] [stderr]   Downloaded handlebars v4.3.4
[INFO] [stderr]   Downloaded build-info-proc v0.0.21
[INFO] [stderr]   Downloaded lzma-sys v0.1.19
[INFO] [stderr]   Downloaded mdbook v0.4.21
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:59a85a07ab18ca8720692f8e61effa1c651d9e2ca591e072c2b212bb91a6b8b5" "/opt/rustwide/cargo-home/bin/cargo" "+506512391b1a75ae450d36c9420978402a91abcc" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6e7d298a5777cab51eeb6088e8f3e5860b6e4d0ae07b800015b9dacf896ac656
[INFO] running `Command { std: "docker" "start" "-a" "6e7d298a5777cab51eeb6088e8f3e5860b6e4d0ae07b800015b9dacf896ac656", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6e7d298a5777cab51eeb6088e8f3e5860b6e4d0ae07b800015b9dacf896ac656", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6e7d298a5777cab51eeb6088e8f3e5860b6e4d0ae07b800015b9dacf896ac656", kill_on_drop: false }`
[INFO] [stdout] 6e7d298a5777cab51eeb6088e8f3e5860b6e4d0ae07b800015b9dacf896ac656
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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=allow" "-e" "RUSTDOCFLAGS=--cap-lints=allow" "-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@sha256:59a85a07ab18ca8720692f8e61effa1c651d9e2ca591e072c2b212bb91a6b8b5" "/opt/rustwide/cargo-home/bin/cargo" "+506512391b1a75ae450d36c9420978402a91abcc" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9a52c96543bf769324ca128dd675e2dd5a3cc677adbef7c833767edc9326a92b
[INFO] running `Command { std: "docker" "start" "-a" "9a52c96543bf769324ca128dd675e2dd5a3cc677adbef7c833767edc9326a92b", kill_on_drop: false }`
[INFO] [stderr]    Compiling unicode-ident v1.0.4
[INFO] [stderr]    Compiling syn v1.0.101
[INFO] [stderr]    Compiling pkg-config v0.3.25
[INFO] [stderr]    Compiling serde_derive v1.0.145
[INFO] [stderr]    Compiling serde v1.0.145
[INFO] [stderr]    Compiling thiserror v1.0.37
[INFO] [stderr]    Compiling libc v0.2.134
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling proc-macro2 v1.0.46
[INFO] [stderr]    Compiling ucd-trie v0.1.5
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/proc-macro2-1.0.46/src/lib.rs:92:30
[INFO] [stdout]    |
[INFO] [stdout] 92 |     feature(proc_macro_span, proc_macro_span_shrink)
[INFO] [stdout]    |                              ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling serde_json v1.0.85
[INFO] [stderr]    Compiling futures-core v0.3.24
[INFO] [stderr]    Compiling anyhow v1.0.65
[INFO] [stderr]    Compiling indexmap v1.9.1
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0635`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `proc-macro2` (lib) due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "9a52c96543bf769324ca128dd675e2dd5a3cc677adbef7c833767edc9326a92b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9a52c96543bf769324ca128dd675e2dd5a3cc677adbef7c833767edc9326a92b", kill_on_drop: false }`
[INFO] [stdout] 9a52c96543bf769324ca128dd675e2dd5a3cc677adbef7c833767edc9326a92b