[INFO] fetching crate higher-free-macro 0.1.0...
[INFO] checking higher-free-macro-0.1.0 against master#cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c for pr-143170
[INFO] extracting crate higher-free-macro 0.1.0 into /workspace/builds/worker-2-tc1/source
[INFO] started tweaking crates.io crate higher-free-macro 0.1.0
[INFO] finished tweaking crates.io crate higher-free-macro 0.1.0
[INFO] tweaked toml for crates.io crate higher-free-macro 0.1.0 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate higher-free-macro 0.1.0 on toolchain cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate higher-free-macro 0.1.0 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" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "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 higher-derive v0.2.0
[INFO] [stderr]   Downloaded unicode-ident v1.0.7
[INFO] [stderr]   Downloaded higher v0.2.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5e4942e4e450f0b393dc85f06d663ed8ea556ce07ff5004299f12f18e149cfa9
[INFO] running `Command { std: "docker" "start" "-a" "5e4942e4e450f0b393dc85f06d663ed8ea556ce07ff5004299f12f18e149cfa9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5e4942e4e450f0b393dc85f06d663ed8ea556ce07ff5004299f12f18e149cfa9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5e4942e4e450f0b393dc85f06d663ed8ea556ce07ff5004299f12f18e149cfa9", kill_on_drop: false }`
[INFO] [stdout] 5e4942e4e450f0b393dc85f06d663ed8ea556ce07ff5004299f12f18e149cfa9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ac6d4210cd1b16186cec4fdcd791a0baed403f0920517369f2dc87fb17cf56b2
[INFO] running `Command { std: "docker" "start" "-a" "ac6d4210cd1b16186cec4fdcd791a0baed403f0920517369f2dc87fb17cf56b2", kill_on_drop: false }`
[INFO] [stderr]    Compiling unicode-ident v1.0.7
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling futures-core v0.3.27
[INFO] [stderr]    Compiling futures-channel v0.3.27
[INFO] [stderr]    Compiling futures-task v0.3.27
[INFO] [stderr]    Compiling libc v0.2.140
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling futures-util v0.3.27
[INFO] [stderr]     Checking futures-sink v0.3.27
[INFO] [stderr]     Checking futures-io v0.3.27
[INFO] [stderr]     Checking pin-project-lite v0.2.9
[INFO] [stderr]    Compiling slab v0.4.8
[INFO] [stderr]    Compiling proc-macro2 v1.0.51
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.51/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" "ac6d4210cd1b16186cec4fdcd791a0baed403f0920517369f2dc87fb17cf56b2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ac6d4210cd1b16186cec4fdcd791a0baed403f0920517369f2dc87fb17cf56b2", kill_on_drop: false }`
[INFO] [stdout] ac6d4210cd1b16186cec4fdcd791a0baed403f0920517369f2dc87fb17cf56b2