[INFO] cloning repository https://github.com/linushahs/rustlings-practice
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/linushahs/rustlings-practice" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flinushahs%2Frustlings-practice", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flinushahs%2Frustlings-practice'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b0b55f3742716149c7342377fa19cc6629cbec7a
[INFO] checking linushahs/rustlings-practice against try#44e31dee3cf6f37b4f652572897bb0eb25c477ee for pr-139763
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flinushahs%2Frustlings-practice" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/linushahs/rustlings-practice on toolchain 44e31dee3cf6f37b4f652572897bb0eb25c477ee
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+44e31dee3cf6f37b4f652572897bb0eb25c477ee" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/linushahs/rustlings-practice
[INFO] finished tweaking git repo https://github.com/linushahs/rustlings-practice
[INFO] tweaked toml for git repo https://github.com/linushahs/rustlings-practice written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/linushahs/rustlings-practice 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" "+44e31dee3cf6f37b4f652572897bb0eb25c477ee" "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-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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:b0b074c097205a61b89e8ad263052f976b2b332c4dc5f02aef1fe52501660d6e" "/opt/rustwide/cargo-home/bin/cargo" "+44e31dee3cf6f37b4f652572897bb0eb25c477ee" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f34eecb07a79d978b59ed7f7a62b20b8f1ebb11ca60d21410b35314fea662ae0
[INFO] running `Command { std: "docker" "start" "-a" "f34eecb07a79d978b59ed7f7a62b20b8f1ebb11ca60d21410b35314fea662ae0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f34eecb07a79d978b59ed7f7a62b20b8f1ebb11ca60d21410b35314fea662ae0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f34eecb07a79d978b59ed7f7a62b20b8f1ebb11ca60d21410b35314fea662ae0", kill_on_drop: false }`
[INFO] [stdout] f34eecb07a79d978b59ed7f7a62b20b8f1ebb11ca60d21410b35314fea662ae0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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:b0b074c097205a61b89e8ad263052f976b2b332c4dc5f02aef1fe52501660d6e" "/opt/rustwide/cargo-home/bin/cargo" "+44e31dee3cf6f37b4f652572897bb0eb25c477ee" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e317b1c09503ec9830ca189d5b8c9ca8e469e4346611d903e56558ef8ee3d21a
[INFO] running `Command { std: "docker" "start" "-a" "e317b1c09503ec9830ca189d5b8c9ca8e469e4346611d903e56558ef8ee3d21a", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.140
[INFO] [stderr]    Compiling proc-macro2 v1.0.53
[INFO] [stderr]    Compiling quote v1.0.26
[INFO] [stderr]    Compiling autocfg v1.1.0
[INFO] [stderr]    Compiling unicode-ident v1.0.8
[INFO] [stderr]    Compiling serde_derive v1.0.158
[INFO] [stderr]    Compiling serde v1.0.158
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]     Checking memchr v2.6.3
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking anstyle v1.0.3
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking utf8parse v0.2.1
[INFO] [stderr]     Checking hashbrown v0.14.0
[INFO] [stderr]     Checking colorchoice v1.0.0
[INFO] [stderr]     Checking anstyle-parse v0.2.1
[INFO] [stderr]     Checking regex-syntax v0.6.29
[INFO] [stderr]    Compiling portable-atomic v1.4.3
[INFO] [stderr]    Compiling slab v0.4.8
[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] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]     Checking anstyle-query v1.0.0
[INFO] [stderr]     Checking equivalent v1.0.1
[INFO] [stderr]     Checking anstream v0.5.0
[INFO] [stderr]     Checking indexmap v2.0.0
[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" "e317b1c09503ec9830ca189d5b8c9ca8e469e4346611d903e56558ef8ee3d21a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e317b1c09503ec9830ca189d5b8c9ca8e469e4346611d903e56558ef8ee3d21a", kill_on_drop: false }`
[INFO] [stdout] e317b1c09503ec9830ca189d5b8c9ca8e469e4346611d903e56558ef8ee3d21a