[INFO] fetching crate viewit 0.1.5...
[INFO] building viewit-0.1.5 against try#4987e9d4227139400384ab59296ffee3b0fb1183 for pr-146237-2
[INFO] extracting crate viewit 0.1.5 into /workspace/builds/worker-5-tc2/source
[INFO] started tweaking crates.io crate viewit 0.1.5
[INFO] finished tweaking crates.io crate viewit 0.1.5
[INFO] tweaked toml for crates.io crate viewit 0.1.5 written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate viewit 0.1.5 on toolchain 4987e9d4227139400384ab59296ffee3b0fb1183
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4987e9d4227139400384ab59296ffee3b0fb1183" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate viewit 0.1.5 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" "+4987e9d4227139400384ab59296ffee3b0fb1183" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+4987e9d4227139400384ab59296ffee3b0fb1183" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 47d922859cf215f004db35bed84de49e514ec802a4b52bb442b34cfb7cf69dce
[INFO] running `Command { std: "docker" "start" "-a" "47d922859cf215f004db35bed84de49e514ec802a4b52bb442b34cfb7cf69dce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "47d922859cf215f004db35bed84de49e514ec802a4b52bb442b34cfb7cf69dce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "47d922859cf215f004db35bed84de49e514ec802a4b52bb442b34cfb7cf69dce", kill_on_drop: false }`
[INFO] [stdout] 47d922859cf215f004db35bed84de49e514ec802a4b52bb442b34cfb7cf69dce
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+4987e9d4227139400384ab59296ffee3b0fb1183" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] cd4a4dac5d0ca8be397323642342e8ff0b76f0e12fa5a47056fc3f37d59b2cd6
[INFO] running `Command { std: "docker" "start" "-a" "cd4a4dac5d0ca8be397323642342e8ff0b76f0e12fa5a47056fc3f37d59b2cd6", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.51
[INFO] [stderr]    Compiling unicode-ident v1.0.8
[INFO] [stderr]    Compiling prettyplease v0.1.24
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.51/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" "cd4a4dac5d0ca8be397323642342e8ff0b76f0e12fa5a47056fc3f37d59b2cd6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cd4a4dac5d0ca8be397323642342e8ff0b76f0e12fa5a47056fc3f37d59b2cd6", kill_on_drop: false }`
[INFO] [stdout] cd4a4dac5d0ca8be397323642342e8ff0b76f0e12fa5a47056fc3f37d59b2cd6