[INFO] cloning repository https://github.com/przprz/rustlings
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/przprz/rustlings" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fprzprz%2Frustlings", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fprzprz%2Frustlings'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a8416f47465b392a15d9b36d5b634b67ca962d52
[INFO] checking przprz/rustlings against try#d83b14207998f47b18a34e930157ac0d7c18b16e for pr-149137
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fprzprz%2Frustlings" "/workspace/builds/worker-1-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/przprz/rustlings
[INFO] finished tweaking git repo https://github.com/przprz/rustlings
[INFO] tweaked toml for git repo https://github.com/przprz/rustlings written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/przprz/rustlings on toolchain d83b14207998f47b18a34e930157ac0d7c18b16e
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+d83b14207998f47b18a34e930157ac0d7c18b16e" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/przprz/rustlings 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" "+d83b14207998f47b18a34e930157ac0d7c18b16e" "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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded argh v0.1.10
[INFO] [stderr]   Downloaded argh_shared v0.1.10
[INFO] [stderr]   Downloaded argh_derive v0.1.10
[INFO] [stderr]   Downloaded home v0.5.4
[INFO] [stderr]   Downloaded console v0.15.5
[INFO] [stderr]   Downloaded syn v2.0.8
[INFO] [stderr]   Downloaded regex v1.7.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+d83b14207998f47b18a34e930157ac0d7c18b16e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 536d365e0a832056550d9b056ce8236d9b31da342248588944f8de711fbf5c49
[INFO] running `Command { std: "docker" "start" "-a" "536d365e0a832056550d9b056ce8236d9b31da342248588944f8de711fbf5c49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "536d365e0a832056550d9b056ce8236d9b31da342248588944f8de711fbf5c49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "536d365e0a832056550d9b056ce8236d9b31da342248588944f8de711fbf5c49", kill_on_drop: false }`
[INFO] [stdout] 536d365e0a832056550d9b056ce8236d9b31da342248588944f8de711fbf5c49
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+d83b14207998f47b18a34e930157ac0d7c18b16e" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 70b17df517d2b55311a9d625d210a9348cabbdb6d4e3165554ce1b45cf919f0d
[INFO] running `Command { std: "docker" "start" "-a" "70b17df517d2b55311a9d625d210a9348cabbdb6d4e3165554ce1b45cf919f0d", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.53
[INFO] [stderr]    Compiling libc v0.2.140
[INFO] [stderr]    Compiling serde_derive v1.0.158
[INFO] [stderr]    Compiling serde v1.0.158
[INFO] [stderr]    Compiling serde_json v1.0.94
[INFO] [stderr]     Checking predicates-core v1.0.6
[INFO] [stderr]     Checking unicode-width v0.1.10
[INFO] [stderr]     Checking lazycell v1.3.0
[INFO] [stderr]    Compiling escargot v0.4.0
[INFO] [stderr]    Compiling argh_shared v0.1.10
[INFO] [stderr]     Checking walkdir v2.3.3
[INFO] [stderr]     Checking termtree v0.4.1
[INFO] [stderr]     Checking float-cmp v0.8.0
[INFO] [stderr]     Checking difference v2.0.0
[INFO] [stderr]     Checking normalize-line-endings v0.3.0
[INFO] [stderr]     Checking regex v1.7.2
[INFO] [stderr]     Checking home v0.5.4
[INFO] [stderr]     Checking predicates-tree v1.0.9
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.53/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] [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" "70b17df517d2b55311a9d625d210a9348cabbdb6d4e3165554ce1b45cf919f0d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "70b17df517d2b55311a9d625d210a9348cabbdb6d4e3165554ce1b45cf919f0d", kill_on_drop: false }`
[INFO] [stdout] 70b17df517d2b55311a9d625d210a9348cabbdb6d4e3165554ce1b45cf919f0d