[INFO] cloning repository https://github.com/Cheukting/rustlings
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Cheukting/rustlings" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCheukting%2Frustlings", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCheukting%2Frustlings'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] adc7ca56901ed1f53659fb8fa139a65423affd13
[INFO] checking Cheukting/rustlings against master#9050733395f7c10560d49f549e022f411fa28cea for pr-146972
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCheukting%2Frustlings" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/Cheukting/rustlings
[INFO] finished tweaking git repo https://github.com/Cheukting/rustlings
[INFO] tweaked toml for git repo https://github.com/Cheukting/rustlings written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/Cheukting/rustlings on toolchain 9050733395f7c10560d49f549e022f411fa28cea
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+9050733395f7c10560d49f549e022f411fa28cea" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/Cheukting/rustlings 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" "+9050733395f7c10560d49f549e022f411fa28cea" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded predicates v1.0.8
[INFO] [stderr]   Downloaded proc-macro2 v1.0.53
[INFO] [stderr]   Downloaded argh_shared v0.1.10
[INFO] [stderr]   Downloaded filetime v0.2.20
[INFO] [stderr]   Downloaded argh_derive v0.1.10
[INFO] [stderr]   Downloaded argh v0.1.10
[INFO] [stderr]   Downloaded console v0.15.5
[INFO] [stderr]   Downloaded net2 v0.2.38
[INFO] [stderr]   Downloaded regex v1.7.2
[INFO] [stderr]   Downloaded float-cmp v0.8.0
[INFO] [stderr]   Downloaded home v0.5.4
[INFO] [stderr]   Downloaded syn v2.0.8
[INFO] [stderr]   Downloaded notify v4.0.17
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+9050733395f7c10560d49f549e022f411fa28cea" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 86f3b26984e8c1842d423ee36023a7ab9b36e5a3d41980a638da177d0e27f09e
[INFO] running `Command { std: "docker" "start" "-a" "86f3b26984e8c1842d423ee36023a7ab9b36e5a3d41980a638da177d0e27f09e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "86f3b26984e8c1842d423ee36023a7ab9b36e5a3d41980a638da177d0e27f09e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "86f3b26984e8c1842d423ee36023a7ab9b36e5a3d41980a638da177d0e27f09e", kill_on_drop: false }`
[INFO] [stdout] 86f3b26984e8c1842d423ee36023a7ab9b36e5a3d41980a638da177d0e27f09e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+9050733395f7c10560d49f549e022f411fa28cea" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c9d6a336a0cd22db4048cf601c08f87cb279097c865ca66e9af13f5a8b465819
[INFO] running `Command { std: "docker" "start" "-a" "c9d6a336a0cd22db4048cf601c08f87cb279097c865ca66e9af13f5a8b465819", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.53
[INFO] [stderr]    Compiling libc v0.2.140
[INFO] [stderr]    Compiling serde_derive v1.0.158
[INFO] [stderr]    Compiling serde v1.0.158
[INFO] [stderr]     Checking lazycell v1.3.0
[INFO] [stderr]    Compiling argh_shared v0.1.10
[INFO] [stderr]     Checking walkdir v2.3.3
[INFO] [stderr]     Checking slab v0.4.8
[INFO] [stderr]     Checking glob v0.3.1
[INFO] [stderr]     Checking regex v1.7.2
[INFO] [stderr]     Checking float-cmp v0.8.0
[INFO] [stderr]     Checking home v0.5.4
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.53/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" "c9d6a336a0cd22db4048cf601c08f87cb279097c865ca66e9af13f5a8b465819", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c9d6a336a0cd22db4048cf601c08f87cb279097c865ca66e9af13f5a8b465819", kill_on_drop: false }`
[INFO] [stdout] c9d6a336a0cd22db4048cf601c08f87cb279097c865ca66e9af13f5a8b465819
