[INFO] fetching crate libknot 0.2.1...
[INFO] checking libknot-0.2.1 against master#ff1737bb00913444173658b4e0b274fd79aabf66 for pr-132712-1
[INFO] extracting crate libknot 0.2.1 into /workspace/builds/worker-6-tc1/source
[INFO] validating manifest of crates.io crate libknot 0.2.1 on toolchain ff1737bb00913444173658b4e0b274fd79aabf66
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ff1737bb00913444173658b4e0b274fd79aabf66" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate libknot 0.2.1
[INFO] finished tweaking crates.io crate libknot 0.2.1
[INFO] tweaked toml for crates.io crate libknot 0.2.1 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate crates.io crate libknot 0.2.1 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" "+ff1737bb00913444173658b4e0b274fd79aabf66" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded proc-macro2 v0.3.5
[INFO] [stderr]   Downloaded unix_socket2 v0.5.4
[INFO] [stderr]   Downloaded clang-sys v0.23.0
[INFO] [stderr]   Downloaded bindgen v0.37.4
[INFO] [stderr]   Downloaded libknot-sys v0.1.0
[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@sha256:4a844ea9eb2546a2d2c7022eacef16ef2e8229c7fbb2c7d4d55a9ceca922f72d" "/opt/rustwide/cargo-home/bin/cargo" "+ff1737bb00913444173658b4e0b274fd79aabf66" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 20cecd494b0a02296761e95c278c5688bb788dfb9d97feaeec06f78005be7a36
[INFO] running `Command { std: "docker" "start" "-a" "20cecd494b0a02296761e95c278c5688bb788dfb9d97feaeec06f78005be7a36", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "20cecd494b0a02296761e95c278c5688bb788dfb9d97feaeec06f78005be7a36", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "20cecd494b0a02296761e95c278c5688bb788dfb9d97feaeec06f78005be7a36", kill_on_drop: false }`
[INFO] [stdout] 20cecd494b0a02296761e95c278c5688bb788dfb9d97feaeec06f78005be7a36
[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@sha256:4a844ea9eb2546a2d2c7022eacef16ef2e8229c7fbb2c7d4d55a9ceca922f72d" "/opt/rustwide/cargo-home/bin/cargo" "+ff1737bb00913444173658b4e0b274fd79aabf66" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 84295b0da53e6d37e888f27dc5c3a3408386a0cdb739b29b813cfc7f36ff19e4
[INFO] running `Command { std: "docker" "start" "-a" "84295b0da53e6d37e888f27dc5c3a3408386a0cdb739b29b813cfc7f36ff19e4", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling libc v0.2.134
[INFO] [stderr]    Compiling proc-macro2 v1.0.46
[INFO] [stderr]    Compiling unicode-ident v1.0.4
[INFO] [stderr]    Compiling quote v1.0.21
[INFO] [stderr]    Compiling syn v1.0.101
[INFO] [stderr]    Compiling cc v1.0.73
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking adler v1.0.2
[INFO] [stderr]     Checking gimli v0.26.2
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling unicode-xid v0.2.4
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]     Checking rustc-demangle v0.1.21
[INFO] [stderr]     Checking regex-syntax v0.6.27
[INFO] [stderr]     Checking termcolor v1.1.3
[INFO] [stderr]     Checking humantime v2.1.0
[INFO] [stderr]     Checking miniz_oxide v0.5.4
[INFO] [stderr]     Checking byteorder v1.4.3
[INFO] [stderr]     Checking fallible-iterator v0.2.0
[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] [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" "84295b0da53e6d37e888f27dc5c3a3408386a0cdb739b29b813cfc7f36ff19e4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "84295b0da53e6d37e888f27dc5c3a3408386a0cdb739b29b813cfc7f36ff19e4", kill_on_drop: false }`
[INFO] [stdout] 84295b0da53e6d37e888f27dc5c3a3408386a0cdb739b29b813cfc7f36ff19e4