[INFO] cloning repository https://github.com/kumarmo2/maelstorm-soln
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/kumarmo2/maelstorm-soln" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkumarmo2%2Fmaelstorm-soln", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkumarmo2%2Fmaelstorm-soln'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 801b0f99a5068489154371233f0c9ff710e77bfc
[INFO] checking kumarmo2/maelstorm-soln against master#cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c for pr-143170
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkumarmo2%2Fmaelstorm-soln" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/kumarmo2/maelstorm-soln
[INFO] finished tweaking git repo https://github.com/kumarmo2/maelstorm-soln
[INFO] tweaked toml for git repo https://github.com/kumarmo2/maelstorm-soln written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/kumarmo2/maelstorm-soln 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 git repo https://github.com/kumarmo2/maelstorm-soln 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]  Downloading crates ...
[INFO] [stderr]   Downloaded serde_derive v1.0.159
[INFO] [stderr]   Downloaded anyhow v1.0.70
[INFO] [stderr]   Downloaded syn v2.0.13
[INFO] [stderr]   Downloaded serde v1.0.159
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] cdfff8b5447b384deb226ac321afd1ad103737b3b87ee0d09e8e8a1bb795895e
[INFO] running `Command { std: "docker" "start" "-a" "cdfff8b5447b384deb226ac321afd1ad103737b3b87ee0d09e8e8a1bb795895e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cdfff8b5447b384deb226ac321afd1ad103737b3b87ee0d09e8e8a1bb795895e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cdfff8b5447b384deb226ac321afd1ad103737b3b87ee0d09e8e8a1bb795895e", kill_on_drop: false }`
[INFO] [stdout] cdfff8b5447b384deb226ac321afd1ad103737b3b87ee0d09e8e8a1bb795895e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] e54d8968344354e88ec610b5a4b7468d7239a979c48843dcb4b04bc7b282bf43
[INFO] running `Command { std: "docker" "start" "-a" "e54d8968344354e88ec610b5a4b7468d7239a979c48843dcb4b04bc7b282bf43", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.56
[INFO] [stderr]    Compiling unicode-ident v1.0.8
[INFO] [stderr]    Compiling quote v1.0.26
[INFO] [stderr]    Compiling serde_derive v1.0.159
[INFO] [stderr]    Compiling serde v1.0.159
[INFO] [stderr]    Compiling serde_json v1.0.96
[INFO] [stderr]    Compiling anyhow v1.0.70
[INFO] [stderr]     Checking itoa v1.0.6
[INFO] [stderr]     Checking ryu v1.0.13
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.56/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] running `Command { std: "docker" "inspect" "e54d8968344354e88ec610b5a4b7468d7239a979c48843dcb4b04bc7b282bf43", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e54d8968344354e88ec610b5a4b7468d7239a979c48843dcb4b04bc7b282bf43", kill_on_drop: false }`
[INFO] [stdout] e54d8968344354e88ec610b5a4b7468d7239a979c48843dcb4b04bc7b282bf43