[INFO] fetching crate virt-ic 0.5.2...
[INFO] testing virt-ic-0.5.2 against master#cdb45c87e2cd43495379f7e867e3cc15dcee9f93 for pr-145838-1
[INFO] extracting crate virt-ic 0.5.2 into /workspace/builds/worker-4-tc1/source
[INFO] started tweaking crates.io crate virt-ic 0.5.2
[INFO] finished tweaking crates.io crate virt-ic 0.5.2
[INFO] tweaked toml for crates.io crate virt-ic 0.5.2 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate virt-ic 0.5.2 on toolchain cdb45c87e2cd43495379f7e867e3cc15dcee9f93
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate virt-ic 0.5.2 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" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded syn v2.0.9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] aa12c53ae3757ad31a4dc976fe9d7fea7cf512e9213b31d6c1d42d0289f8876f
[INFO] running `Command { std: "docker" "start" "-a" "aa12c53ae3757ad31a4dc976fe9d7fea7cf512e9213b31d6c1d42d0289f8876f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "aa12c53ae3757ad31a4dc976fe9d7fea7cf512e9213b31d6c1d42d0289f8876f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "aa12c53ae3757ad31a4dc976fe9d7fea7cf512e9213b31d6c1d42d0289f8876f", kill_on_drop: false }`
[INFO] [stdout] aa12c53ae3757ad31a4dc976fe9d7fea7cf512e9213b31d6c1d42d0289f8876f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a90b55bfb37154b646522a00a59c989f0581d51287cb7ec7251bc16fc61ff079
[INFO] running `Command { std: "docker" "start" "-a" "a90b55bfb37154b646522a00a59c989f0581d51287cb7ec7251bc16fc61ff079", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.53
[INFO] [stderr]    Compiling libc v0.2.140
[INFO] [stderr]    Compiling serde v1.0.158
[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" "a90b55bfb37154b646522a00a59c989f0581d51287cb7ec7251bc16fc61ff079", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a90b55bfb37154b646522a00a59c989f0581d51287cb7ec7251bc16fc61ff079", kill_on_drop: false }`
[INFO] [stdout] a90b55bfb37154b646522a00a59c989f0581d51287cb7ec7251bc16fc61ff079