[INFO] cloning repository https://github.com/senmeannrealwat/rustlings-solution
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/senmeannrealwat/rustlings-solution" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsenmeannrealwat%2Frustlings-solution", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsenmeannrealwat%2Frustlings-solution'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ba434536dac0210eb9436b7f61c684532d5f588a
[INFO] checking senmeannrealwat/rustlings-solution/ba434536dac0210eb9436b7f61c684532d5f588a against master#bd71213cf0a765705e7d72a099151bd4eb465ccb for pr-123864
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsenmeannrealwat%2Frustlings-solution" "/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/senmeannrealwat/rustlings-solution on toolchain bd71213cf0a765705e7d72a099151bd4eb465ccb
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+bd71213cf0a765705e7d72a099151bd4eb465ccb" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/senmeannrealwat/rustlings-solution
[INFO] finished tweaking git repo https://github.com/senmeannrealwat/rustlings-solution
[INFO] tweaked toml for git repo https://github.com/senmeannrealwat/rustlings-solution written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/senmeannrealwat/rustlings-solution 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" "+bd71213cf0a765705e7d72a099151bd4eb465ccb" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+bd71213cf0a765705e7d72a099151bd4eb465ccb" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9da5462c85cd7ec812ab5b7cd558ae406a31722f991844845184a6798d848e39
[INFO] running `Command { std: "docker" "start" "-a" "9da5462c85cd7ec812ab5b7cd558ae406a31722f991844845184a6798d848e39", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9da5462c85cd7ec812ab5b7cd558ae406a31722f991844845184a6798d848e39", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9da5462c85cd7ec812ab5b7cd558ae406a31722f991844845184a6798d848e39", kill_on_drop: false }`
[INFO] [stdout] 9da5462c85cd7ec812ab5b7cd558ae406a31722f991844845184a6798d848e39
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+bd71213cf0a765705e7d72a099151bd4eb465ccb" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a138c462ee47adcd44478f2b07c3d8bfd4ed552970badc1f3cbc133a9f1a21c1
[INFO] running `Command { std: "docker" "start" "-a" "a138c462ee47adcd44478f2b07c3d8bfd4ed552970badc1f3cbc133a9f1a21c1", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.140
[INFO] [stderr]    Compiling proc-macro2 v1.0.53
[INFO] [stderr]    Compiling quote v1.0.26
[INFO] [stderr]    Compiling unicode-ident v1.0.8
[INFO] [stderr]    Compiling serde_derive v1.0.158
[INFO] [stderr]    Compiling serde v1.0.158
[INFO] [stderr]     Checking memchr v2.6.3
[INFO] [stderr]     Checking anstyle v1.0.3
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling portable-atomic v1.4.3
[INFO] [stderr]     Checking regex-syntax v0.6.29
[INFO] [stderr]     Checking hashbrown v0.14.0
[INFO] [stderr]     Checking anstream v0.5.0
[INFO] [stderr]     Checking aho-corasick v0.7.20
[INFO] [stderr]     Checking clap_lex v0.5.1
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/proc-macro2-1.0.53/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 doc-comment v0.3.3
[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" "a138c462ee47adcd44478f2b07c3d8bfd4ed552970badc1f3cbc133a9f1a21c1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a138c462ee47adcd44478f2b07c3d8bfd4ed552970badc1f3cbc133a9f1a21c1", kill_on_drop: false }`
[INFO] [stdout] a138c462ee47adcd44478f2b07c3d8bfd4ed552970badc1f3cbc133a9f1a21c1