[INFO] cloning repository https://github.com/BrookJeynes/flashcards-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/BrookJeynes/flashcards-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBrookJeynes%2Fflashcards-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBrookJeynes%2Fflashcards-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 6f85eafdba9b3e8c87a8ba11c847187a15b81c09
[INFO] checking BrookJeynes/flashcards-rs against master#779e19d8baa3e3625bd4fc5c85cbb2ad47b43155 for pr-147589-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBrookJeynes%2Fflashcards-rs" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/BrookJeynes/flashcards-rs
[INFO] finished tweaking git repo https://github.com/BrookJeynes/flashcards-rs
[INFO] tweaked toml for git repo https://github.com/BrookJeynes/flashcards-rs written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/BrookJeynes/flashcards-rs on toolchain 779e19d8baa3e3625bd4fc5c85cbb2ad47b43155
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+779e19d8baa3e3625bd4fc5c85cbb2ad47b43155" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/BrookJeynes/flashcards-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" "+779e19d8baa3e3625bd4fc5c85cbb2ad47b43155" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded shuffle v0.1.7
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+779e19d8baa3e3625bd4fc5c85cbb2ad47b43155" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8209504bac31ed82ce828d56dc7c95a85fa22fe788a3b2cee181627c7bd39651
[INFO] running `Command { std: "docker" "start" "-a" "8209504bac31ed82ce828d56dc7c95a85fa22fe788a3b2cee181627c7bd39651", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8209504bac31ed82ce828d56dc7c95a85fa22fe788a3b2cee181627c7bd39651", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8209504bac31ed82ce828d56dc7c95a85fa22fe788a3b2cee181627c7bd39651", kill_on_drop: false }`
[INFO] [stdout] 8209504bac31ed82ce828d56dc7c95a85fa22fe788a3b2cee181627c7bd39651
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+779e19d8baa3e3625bd4fc5c85cbb2ad47b43155" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c5cdc8838d53964373fe619e795c369853cd369185942a9dad879a198d1b06b8
[INFO] running `Command { std: "docker" "start" "-a" "c5cdc8838d53964373fe619e795c369853cd369185942a9dad879a198d1b06b8", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.139
[INFO] [stderr]    Compiling syn v1.0.107
[INFO] [stderr]    Compiling parking_lot_core v0.9.6
[INFO] [stderr]    Compiling signal-hook v0.3.14
[INFO] [stderr]     Checking smallvec v1.10.0
[INFO] [stderr]     Checking either v1.8.0
[INFO] [stderr]    Compiling serde_json v1.0.91
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]     Checking radium v0.3.0
[INFO] [stderr]     Checking cassowary v0.3.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.49
[INFO] [stderr]    Compiling lock_api v0.4.9
[INFO] [stderr]     Checking unicode-width v0.1.10
[INFO] [stderr]     Checking itoa v1.0.5
[INFO] [stderr]     Checking unicode-segmentation v1.10.0
[INFO] [stderr]     Checking ryu v1.0.12
[INFO] [stderr]     Checking bitvec v0.17.4
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.49/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 xcb v0.8.2
[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" "c5cdc8838d53964373fe619e795c369853cd369185942a9dad879a198d1b06b8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c5cdc8838d53964373fe619e795c369853cd369185942a9dad879a198d1b06b8", kill_on_drop: false }`
[INFO] [stdout] c5cdc8838d53964373fe619e795c369853cd369185942a9dad879a198d1b06b8
