[INFO] cloning repository https://github.com/nihilistkitten/ext2-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/nihilistkitten/ext2-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnihilistkitten%2Fext2-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnihilistkitten%2Fext2-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a9447b4409a608d29cf2588a32de3012f5ee9f61
[INFO] checking nihilistkitten/ext2-rs against try#3c75d5844aa65b4aa19243ac44ceda49fe4e61ca for pr-143545
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnihilistkitten%2Fext2-rs" "/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/nihilistkitten/ext2-rs
[INFO] finished tweaking git repo https://github.com/nihilistkitten/ext2-rs
[INFO] tweaked toml for git repo https://github.com/nihilistkitten/ext2-rs written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/nihilistkitten/ext2-rs on toolchain 3c75d5844aa65b4aa19243ac44ceda49fe4e61ca
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3c75d5844aa65b4aa19243ac44ceda49fe4e61ca" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/nihilistkitten/ext2-rs 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" "+3c75d5844aa65b4aa19243ac44ceda49fe4e61ca" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded null-terminated v0.3.17
[INFO] [stderr]   Downloaded byte-strings-proc_macros v0.2.2
[INFO] [stderr]   Downloaded utf v0.1.6
[INFO] [stderr]   Downloaded bitflags v2.0.2
[INFO] [stderr]   Downloaded zerocopy-derive v0.3.2
[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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+3c75d5844aa65b4aa19243ac44ceda49fe4e61ca" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 187b9149d4ae04330e776cf10a6f2ec36dbf925cb840944ea44249257fb92f64
[INFO] running `Command { std: "docker" "start" "-a" "187b9149d4ae04330e776cf10a6f2ec36dbf925cb840944ea44249257fb92f64", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "187b9149d4ae04330e776cf10a6f2ec36dbf925cb840944ea44249257fb92f64", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "187b9149d4ae04330e776cf10a6f2ec36dbf925cb840944ea44249257fb92f64", kill_on_drop: false }`
[INFO] [stdout] 187b9149d4ae04330e776cf10a6f2ec36dbf925cb840944ea44249257fb92f64
[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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+3c75d5844aa65b4aa19243ac44ceda49fe4e61ca" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 774f9312ac1ca020c4c8e1074bf9b01b5f7c0b2ec8e3648e0279ef9ccd7078f4
[INFO] running `Command { std: "docker" "start" "-a" "774f9312ac1ca020c4c8e1074bf9b01b5f7c0b2ec8e3648e0279ef9ccd7078f4", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.52
[INFO] [stderr]    Compiling unicode-ident v1.0.8
[INFO] [stderr]    Compiling quote v1.0.26
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]     Checking byteorder v1.4.3
[INFO] [stderr]     Checking utf v0.1.6
[INFO] [stderr]     Checking bitflags v2.0.2
[INFO] [stderr]     Checking unreachable v1.0.0
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.52/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" "774f9312ac1ca020c4c8e1074bf9b01b5f7c0b2ec8e3648e0279ef9ccd7078f4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "774f9312ac1ca020c4c8e1074bf9b01b5f7c0b2ec8e3648e0279ef9ccd7078f4", kill_on_drop: false }`
[INFO] [stdout] 774f9312ac1ca020c4c8e1074bf9b01b5f7c0b2ec8e3648e0279ef9ccd7078f4