[INFO] fetching crate mdbook-linkcheck 0.7.7...
[INFO] testing mdbook-linkcheck-0.7.7 against try#8de4c7234dd9b97c9d76b58671343fdbbc9a433e+target=x86_64-unknown-linux-musl for musl_upgrade_1_2_5_with_libc_patch_0
[INFO] extracting crate mdbook-linkcheck 0.7.7 into /workspace/builds/worker-6-tc1/source
[INFO] removed /workspace/builds/worker-6-tc1/source/.cargo/config
[INFO] started tweaking crates.io crate mdbook-linkcheck 0.7.7
[INFO] finished tweaking crates.io crate mdbook-linkcheck 0.7.7
[INFO] tweaked toml for crates.io crate mdbook-linkcheck 0.7.7 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate mdbook-linkcheck 0.7.7 on toolchain 8de4c7234dd9b97c9d76b58671343fdbbc9a433e
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate mdbook-linkcheck 0.7.7 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" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded pest_generator v2.4.0
[INFO] [stderr]   Downloaded opener v0.5.0
[INFO] [stderr]   Downloaded pest_meta v2.4.0
[INFO] [stderr]   Downloaded linkify v0.7.0
[INFO] [stderr]   Downloaded iana-time-zone v0.1.50
[INFO] [stderr]   Downloaded env_logger v0.9.1
[INFO] [stderr]   Downloaded linkcheck v0.4.1
[INFO] [stderr]   Downloaded handlebars v4.3.4
[INFO] [stderr]   Downloaded pest_derive v2.4.0
[INFO] [stderr]   Downloaded pest v2.4.0
[INFO] [stderr]   Downloaded mdbook v0.4.21
[INFO] [stderr]   Downloaded openssl-src v111.22.0+1.1.1q
[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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 435762c702a50b961bb28b09eb90a618ebf3c852958a694bd56e9c90cd60729b
[INFO] running `Command { std: "docker" "start" "-a" "435762c702a50b961bb28b09eb90a618ebf3c852958a694bd56e9c90cd60729b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "435762c702a50b961bb28b09eb90a618ebf3c852958a694bd56e9c90cd60729b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "435762c702a50b961bb28b09eb90a618ebf3c852958a694bd56e9c90cd60729b", kill_on_drop: false }`
[INFO] [stdout] 435762c702a50b961bb28b09eb90a618ebf3c852958a694bd56e9c90cd60729b
[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=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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "build" "--frozen" "--message-format=json" "--target" "x86_64-unknown-linux-musl", kill_on_drop: false }`
[INFO] [stdout] a1983cf5121fc5b507349b5b8bb0c4a6b37d03be85f3e8ffeeb1da8d8bc475c8
[INFO] running `Command { std: "docker" "start" "-a" "a1983cf5121fc5b507349b5b8bb0c4a6b37d03be85f3e8ffeeb1da8d8bc475c8", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.46
[INFO] [stderr]    Compiling syn v1.0.101
[INFO] [stderr]    Compiling libc v0.2.134
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]    Compiling serde_derive v1.0.145
[INFO] [stderr]    Compiling thiserror v1.0.37
[INFO] [stderr]    Compiling cc v1.0.73
[INFO] [stderr]    Compiling serde v1.0.145
[INFO] [stderr]    Compiling pkg-config v0.3.25
[INFO] [stderr]    Compiling indexmap v1.9.1
[INFO] [stderr]    Compiling futures-channel v0.3.24
[INFO] [stderr]    Compiling tokio v1.21.2
[INFO] [stderr]    Compiling hashbrown v0.12.3
[INFO] [stderr]    Compiling unicode-width v0.1.10
[INFO] [stderr]    Compiling openssl v0.10.42
[INFO] [stderr]    Compiling unicase v2.6.0
[INFO] [stderr]    Compiling tinyvec_macros v0.1.0
[INFO] [stderr]    Compiling native-tls v0.2.10
[INFO] [stderr]    Compiling ucd-trie v0.1.5
[INFO] [stderr]    Compiling tinyvec v1.6.0
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling once_cell v1.15.0
[INFO] [stderr]    Compiling try-lock v0.2.3
[INFO] [stderr]    Compiling percent-encoding v2.2.0
[INFO] [stderr]    Compiling want v0.3.0
[INFO] [stderr]    Compiling form_urlencoded v1.1.0
[INFO] [stderr]    Compiling http-body v0.4.5
[INFO] [stderr]    Compiling num-integer v0.1.45
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/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 httpdate v1.0.2
[INFO] [stderr]    Compiling encoding_rs v0.8.31
[INFO] [stderr]    Compiling serde_json v1.0.85
[INFO] [stderr]    Compiling unicode-bidi v0.3.8
[INFO] [stderr]    Compiling clap_lex v0.2.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling aho-corasick v0.7.19
[INFO] [stderr]    Compiling textwrap v0.15.1
[INFO] [stderr]    Compiling regex-syntax v0.6.27
[INFO] [stderr]    Compiling pulldown-cmark v0.8.0
[INFO] [stderr]    Compiling openssl-src v111.22.0+1.1.1q
[INFO] [stderr]    Compiling regex-automata v0.1.10
[INFO] [stderr]    Compiling unicode-segmentation v1.10.0
[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 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "a1983cf5121fc5b507349b5b8bb0c4a6b37d03be85f3e8ffeeb1da8d8bc475c8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a1983cf5121fc5b507349b5b8bb0c4a6b37d03be85f3e8ffeeb1da8d8bc475c8", kill_on_drop: false }`
[INFO] [stdout] a1983cf5121fc5b507349b5b8bb0c4a6b37d03be85f3e8ffeeb1da8d8bc475c8