[INFO] cloning repository https://github.com/Shnob/rust-mandelbrot
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Shnob/rust-mandelbrot" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FShnob%2Frust-mandelbrot", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FShnob%2Frust-mandelbrot'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d35531eac70e6833e8eb4f04ec2faf1ab90529e7
[INFO] checking Shnob/rust-mandelbrot against try#50b21af28e291c419ae81eebcb7705fb4200dc90 for pr-135167
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FShnob%2Frust-mandelbrot" "/workspace/builds/worker-3-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Shnob/rust-mandelbrot on toolchain 50b21af28e291c419ae81eebcb7705fb4200dc90
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+50b21af28e291c419ae81eebcb7705fb4200dc90" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Shnob/rust-mandelbrot
[INFO] finished tweaking git repo https://github.com/Shnob/rust-mandelbrot
[INFO] tweaked toml for git repo https://github.com/Shnob/rust-mandelbrot written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/Shnob/rust-mandelbrot 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" "+50b21af28e291c419ae81eebcb7705fb4200dc90" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+50b21af28e291c419ae81eebcb7705fb4200dc90" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 66fc62f0c8a3155f222fcb600a9d312565f6414a81da1b96445b51bf5a26b0f3
[INFO] running `Command { std: "docker" "start" "-a" "66fc62f0c8a3155f222fcb600a9d312565f6414a81da1b96445b51bf5a26b0f3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "66fc62f0c8a3155f222fcb600a9d312565f6414a81da1b96445b51bf5a26b0f3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "66fc62f0c8a3155f222fcb600a9d312565f6414a81da1b96445b51bf5a26b0f3", kill_on_drop: false }`
[INFO] [stdout] 66fc62f0c8a3155f222fcb600a9d312565f6414a81da1b96445b51bf5a26b0f3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+50b21af28e291c419ae81eebcb7705fb4200dc90" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c4219a3fb24987e813bc3c9acd617b595168f20a82ec3406f5a71897ded69914
[INFO] running `Command { std: "docker" "start" "-a" "c4219a3fb24987e813bc3c9acd617b595168f20a82ec3406f5a71897ded69914", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.141
[INFO] [stderr]    Compiling crossbeam-utils v0.8.15
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]    Compiling memoffset v0.8.0
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.14
[INFO] [stderr]    Compiling proc-macro2 v1.0.56
[INFO] [stderr]    Compiling quote v1.0.26
[INFO] [stderr]    Compiling unicode-ident v1.0.8
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling lock_api v0.4.9
[INFO] [stderr]     Checking adler v1.0.2
[INFO] [stderr]    Compiling crc32fast v1.3.2
[INFO] [stderr]     Checking miniz_oxide v0.6.2
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling futures-core v0.3.28
[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] [stderr]    Compiling num-integer v0.1.45
[INFO] [stderr]     Checking either v1.8.1
[INFO] [stderr]     Checking crossbeam-channel v0.5.7
[INFO] [stderr]     Checking spin v0.9.8
[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" "c4219a3fb24987e813bc3c9acd617b595168f20a82ec3406f5a71897ded69914", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c4219a3fb24987e813bc3c9acd617b595168f20a82ec3406f5a71897ded69914", kill_on_drop: false }`
[INFO] [stdout] c4219a3fb24987e813bc3c9acd617b595168f20a82ec3406f5a71897ded69914