[INFO] cloning repository https://github.com/pzdkn/merkle-tree
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/pzdkn/merkle-tree" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpzdkn%2Fmerkle-tree", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpzdkn%2Fmerkle-tree'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8b0f9d37b56acd7866c4835f4dd21296933a96e8
[INFO] checking pzdkn/merkle-tree against master#8c32e313cccf7df531e2d49ffb8227bb92304aee for pr-145608-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpzdkn%2Fmerkle-tree" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/pzdkn/merkle-tree
[INFO] finished tweaking git repo https://github.com/pzdkn/merkle-tree
[INFO] tweaked toml for git repo https://github.com/pzdkn/merkle-tree written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/pzdkn/merkle-tree on toolchain 8c32e313cccf7df531e2d49ffb8227bb92304aee
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+8c32e313cccf7df531e2d49ffb8227bb92304aee" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/pzdkn/merkle-tree 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" "+8c32e313cccf7df531e2d49ffb8227bb92304aee" "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 semver v1.0.16
[INFO] [stderr]   Downloaded libc v0.2.138
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+8c32e313cccf7df531e2d49ffb8227bb92304aee" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ea17685cf751acd5bcf502b3aaf40c954ba04648f8023ef89b262fc6fba3582d
[INFO] running `Command { std: "docker" "start" "-a" "ea17685cf751acd5bcf502b3aaf40c954ba04648f8023ef89b262fc6fba3582d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ea17685cf751acd5bcf502b3aaf40c954ba04648f8023ef89b262fc6fba3582d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ea17685cf751acd5bcf502b3aaf40c954ba04648f8023ef89b262fc6fba3582d", kill_on_drop: false }`
[INFO] [stdout] ea17685cf751acd5bcf502b3aaf40c954ba04648f8023ef89b262fc6fba3582d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+8c32e313cccf7df531e2d49ffb8227bb92304aee" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] beccb3e6d9329903bff2b6901181f72502d4260e71d00117a097ad0bf9810cb8
[INFO] running `Command { std: "docker" "start" "-a" "beccb3e6d9329903bff2b6901181f72502d4260e71d00117a097ad0bf9810cb8", kill_on_drop: false }`
[INFO] [stderr]     Checking generic-array v0.14.6
[INFO] [stderr]    Compiling syn v1.0.107
[INFO] [stderr]     Checking cpufeatures v0.2.5
[INFO] [stderr]    Compiling proc-macro2 v1.0.49
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.49/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" "beccb3e6d9329903bff2b6901181f72502d4260e71d00117a097ad0bf9810cb8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "beccb3e6d9329903bff2b6901181f72502d4260e71d00117a097ad0bf9810cb8", kill_on_drop: false }`
[INFO] [stdout] beccb3e6d9329903bff2b6901181f72502d4260e71d00117a097ad0bf9810cb8