[INFO] cloning repository https://github.com/IsseW/dense_strings
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/IsseW/dense_strings" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FIsseW%2Fdense_strings", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FIsseW%2Fdense_strings'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c7af5e0dda8db58dfe0af6ee4cf6e9aeff018aa2
[INFO] building IsseW/dense_strings against master#ad211ced81509462cdfe4c29ed10f97279a0acae for pr-135216
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FIsseW%2Fdense_strings" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/IsseW/dense_strings on toolchain ad211ced81509462cdfe4c29ed10f97279a0acae
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ad211ced81509462cdfe4c29ed10f97279a0acae" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/IsseW/dense_strings
[INFO] finished tweaking git repo https://github.com/IsseW/dense_strings
[INFO] tweaked toml for git repo https://github.com/IsseW/dense_strings written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/IsseW/dense_strings 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" "+ad211ced81509462cdfe4c29ed10f97279a0acae" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded syn v2.0.14
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+ad211ced81509462cdfe4c29ed10f97279a0acae" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0f95b34510b31371ed99914ae747d89ee84d184f21737fe191a455dde5a6c7cc
[INFO] running `Command { std: "docker" "start" "-a" "0f95b34510b31371ed99914ae747d89ee84d184f21737fe191a455dde5a6c7cc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0f95b34510b31371ed99914ae747d89ee84d184f21737fe191a455dde5a6c7cc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0f95b34510b31371ed99914ae747d89ee84d184f21737fe191a455dde5a6c7cc", kill_on_drop: false }`
[INFO] [stdout] 0f95b34510b31371ed99914ae747d89ee84d184f21737fe191a455dde5a6c7cc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+ad211ced81509462cdfe4c29ed10f97279a0acae" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5bd4d3d8dcff33c817a387e79136d302641371ca2151753a1bb75a2cf57a2c06
[INFO] running `Command { std: "docker" "start" "-a" "5bd4d3d8dcff33c817a387e79136d302641371ca2151753a1bb75a2cf57a2c06", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.56
[INFO] [stderr]    Compiling quote v1.0.26
[INFO] [stderr]    Compiling unicode-ident v1.0.8
[INFO] [stderr]    Compiling serde_derive v1.0.160
[INFO] [stderr]    Compiling serde v1.0.160
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.56/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] error: could not compile `proc-macro2` (lib) due to 1 previous error
[INFO] [stdout] For more information about this error, try `rustc --explain E0635`.
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "5bd4d3d8dcff33c817a387e79136d302641371ca2151753a1bb75a2cf57a2c06", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5bd4d3d8dcff33c817a387e79136d302641371ca2151753a1bb75a2cf57a2c06", kill_on_drop: false }`
[INFO] [stdout] 5bd4d3d8dcff33c817a387e79136d302641371ca2151753a1bb75a2cf57a2c06
