[INFO] fetching crate nostd-float-math-monitor 0.0.8...
[INFO] testing nostd-float-math-monitor-0.0.8 against try#2440211fe03bc45c89b6dc1a3df18382ce91e32b for pr-146098-1
[INFO] extracting crate nostd-float-math-monitor 0.0.8 into /workspace/builds/worker-0-tc2/source
[INFO] started tweaking crates.io crate nostd-float-math-monitor 0.0.8
[INFO] finished tweaking crates.io crate nostd-float-math-monitor 0.0.8
[INFO] tweaked toml for crates.io crate nostd-float-math-monitor 0.0.8 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate nostd-float-math-monitor 0.0.8 on toolchain 2440211fe03bc45c89b6dc1a3df18382ce91e32b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2440211fe03bc45c89b6dc1a3df18382ce91e32b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate nostd-float-math-monitor 0.0.8 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" "+2440211fe03bc45c89b6dc1a3df18382ce91e32b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+2440211fe03bc45c89b6dc1a3df18382ce91e32b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fd243c741f2d522a9cb0bc8bc63ebda3411a5eb86c556ea8ce4b85bf18bc483d
[INFO] running `Command { std: "docker" "start" "-a" "fd243c741f2d522a9cb0bc8bc63ebda3411a5eb86c556ea8ce4b85bf18bc483d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fd243c741f2d522a9cb0bc8bc63ebda3411a5eb86c556ea8ce4b85bf18bc483d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fd243c741f2d522a9cb0bc8bc63ebda3411a5eb86c556ea8ce4b85bf18bc483d", kill_on_drop: false }`
[INFO] [stdout] fd243c741f2d522a9cb0bc8bc63ebda3411a5eb86c556ea8ce4b85bf18bc483d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+2440211fe03bc45c89b6dc1a3df18382ce91e32b" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7d6a6ec1e6310c42ebd960bfc6b85752ec4a90ea8268bffebe677a3f6a0ae5eb
[INFO] running `Command { std: "docker" "start" "-a" "7d6a6ec1e6310c42ebd960bfc6b85752ec4a90ea8268bffebe677a3f6a0ae5eb", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.54
[INFO] [stderr]    Compiling quote v1.0.26
[INFO] [stderr]    Compiling unicode-ident v1.0.8
[INFO] [stderr]    Compiling serde_derive v1.0.159
[INFO] [stderr]    Compiling serde v1.0.159
[INFO] [stderr]    Compiling libc v0.2.140
[INFO] [stderr]    Compiling indexmap v1.9.3
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling cc v1.0.79
[INFO] [stderr]    Compiling num-integer v0.1.45
[INFO] [stderr]    Compiling gimli v0.27.2
[INFO] [stderr]    Compiling winnow v0.4.1
[INFO] [stderr]    Compiling error-chain v0.12.4
[INFO] [stderr]    Compiling miniz_oxide v0.6.2
[INFO] [stderr]    Compiling aho-corasick v0.7.20
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.54/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" "7d6a6ec1e6310c42ebd960bfc6b85752ec4a90ea8268bffebe677a3f6a0ae5eb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7d6a6ec1e6310c42ebd960bfc6b85752ec4a90ea8268bffebe677a3f6a0ae5eb", kill_on_drop: false }`
[INFO] [stdout] 7d6a6ec1e6310c42ebd960bfc6b85752ec4a90ea8268bffebe677a3f6a0ae5eb