[INFO] fetching crate vulkano_maybe_molten 0.30.1...
[INFO] building vulkano_maybe_molten-0.30.1 against try#4987e9d4227139400384ab59296ffee3b0fb1183 for pr-146237-2
[INFO] extracting crate vulkano_maybe_molten 0.30.1 into /workspace/builds/worker-6-tc2/source
[INFO] started tweaking crates.io crate vulkano_maybe_molten 0.30.1
[INFO] finished tweaking crates.io crate vulkano_maybe_molten 0.30.1
[INFO] tweaked toml for crates.io crate vulkano_maybe_molten 0.30.1 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate vulkano_maybe_molten 0.30.1 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 vulkano_maybe_molten 0.30.1 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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] 5e69b3b7ec37bcd72eee5d985d77cd3f5037323e3c6b52d0f3206d7368318b26
[INFO] running `Command { std: "docker" "start" "-a" "5e69b3b7ec37bcd72eee5d985d77cd3f5037323e3c6b52d0f3206d7368318b26", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5e69b3b7ec37bcd72eee5d985d77cd3f5037323e3c6b52d0f3206d7368318b26", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5e69b3b7ec37bcd72eee5d985d77cd3f5037323e3c6b52d0f3206d7368318b26", kill_on_drop: false }`
[INFO] [stdout] 5e69b3b7ec37bcd72eee5d985d77cd3f5037323e3c6b52d0f3206d7368318b26
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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] 16ac89f82ebc003522568681d2484a30460d96b2a6b20bc916e47993313abf0e
[INFO] running `Command { std: "docker" "start" "-a" "16ac89f82ebc003522568681d2484a30460d96b2a6b20bc916e47993313abf0e", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.46
[INFO] [stderr]    Compiling unicode-ident v1.0.4
[INFO] [stderr]    Compiling syn v1.0.101
[INFO] [stderr]    Compiling serde_derive v1.0.145
[INFO] [stderr]    Compiling serde v1.0.145
[INFO] [stderr]    Compiling libc v0.2.134
[INFO] [stderr]    Compiling serde_json v1.0.85
[INFO] [stderr]    Compiling regex-syntax v0.6.27
[INFO] [stderr]    Compiling itoa v1.0.3
[INFO] [stderr]    Compiling ryu v1.0.11
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling indexmap v1.9.1
[INFO] [stderr]    Compiling lock_api v0.4.9
[INFO] [stderr]    Compiling hashbrown v0.12.3
[INFO] [stderr]    Compiling xml-rs v0.8.4
[INFO] [stderr]    Compiling crossbeam-utils v0.8.12
[INFO] [stderr]    Compiling smallvec v1.10.0
[INFO] [stderr]    Compiling crossbeam-queue v0.3.6
[INFO] [stderr]    Compiling ash v0.37.0+1.3.209
[INFO] [stderr]    Compiling libloading v0.7.3
[INFO] [stderr]    Compiling half v1.8.2
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.46/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] [stderr]    Compiling vk-parse v0.7.0
[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" "16ac89f82ebc003522568681d2484a30460d96b2a6b20bc916e47993313abf0e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "16ac89f82ebc003522568681d2484a30460d96b2a6b20bc916e47993313abf0e", kill_on_drop: false }`
[INFO] [stdout] 16ac89f82ebc003522568681d2484a30460d96b2a6b20bc916e47993313abf0e