[INFO] cloning repository https://github.com/reesdavison/rustlings
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/reesdavison/rustlings" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Freesdavison%2Frustlings", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Freesdavison%2Frustlings'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1aec765dce265a032248ad5a9fbf932be9b5df0e
[INFO] checking reesdavison/rustlings against try#e658ebe4ffa1b515cd2ef06dd428d0d063e2ae6b for pr-144896
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Freesdavison%2Frustlings" "/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/reesdavison/rustlings
[INFO] finished tweaking git repo https://github.com/reesdavison/rustlings
[INFO] tweaked toml for git repo https://github.com/reesdavison/rustlings written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/reesdavison/rustlings on toolchain e658ebe4ffa1b515cd2ef06dd428d0d063e2ae6b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+e658ebe4ffa1b515cd2ef06dd428d0d063e2ae6b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/reesdavison/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" "+e658ebe4ffa1b515cd2ef06dd428d0d063e2ae6b" "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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded argh v0.1.10
[INFO] [stderr]   Downloaded argh_shared v0.1.10
[INFO] [stderr]   Downloaded argh_derive v0.1.10
[INFO] [stderr]   Downloaded syn v2.0.8
[INFO] [stderr]   Downloaded regex v1.7.2
[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:ae6f63d130afcfff7f91f5ba9fdb2a74d52830289c6a2ea2d23a94dcfb480a0d" "/opt/rustwide/cargo-home/bin/cargo" "+e658ebe4ffa1b515cd2ef06dd428d0d063e2ae6b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 24cfed2fc1509b520dafcf00766232e39278b280099e72807270d51ac014a160
[INFO] running `Command { std: "docker" "start" "-a" "24cfed2fc1509b520dafcf00766232e39278b280099e72807270d51ac014a160", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "24cfed2fc1509b520dafcf00766232e39278b280099e72807270d51ac014a160", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "24cfed2fc1509b520dafcf00766232e39278b280099e72807270d51ac014a160", kill_on_drop: false }`
[INFO] [stdout] 24cfed2fc1509b520dafcf00766232e39278b280099e72807270d51ac014a160
[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:ae6f63d130afcfff7f91f5ba9fdb2a74d52830289c6a2ea2d23a94dcfb480a0d" "/opt/rustwide/cargo-home/bin/cargo" "+e658ebe4ffa1b515cd2ef06dd428d0d063e2ae6b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6c0d36d7ce9552c3ebace255cd6d6cf0bfea7a71b3288d9bd9f84a3679529133
[INFO] running `Command { std: "docker" "start" "-a" "6c0d36d7ce9552c3ebace255cd6d6cf0bfea7a71b3288d9bd9f84a3679529133", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.53
[INFO] [stderr]    Compiling unicode-ident v1.0.8
[INFO] [stderr]    Compiling quote v1.0.26
[INFO] [stderr]    Compiling libc v0.2.140
[INFO] [stderr]    Compiling serde_derive v1.0.158
[INFO] [stderr]    Compiling serde v1.0.158
[INFO] [stderr]    Compiling serde_json v1.0.94
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]     Checking regex-syntax v0.6.29
[INFO] [stderr]     Checking itoa v1.0.6
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling slab v0.4.8
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]     Checking ryu v1.0.13
[INFO] [stderr]     Checking same-file v1.0.6
[INFO] [stderr]    Compiling escargot v0.4.0
[INFO] [stderr]     Checking predicates-core v1.0.6
[INFO] [stderr]    Compiling argh_shared v0.1.10
[INFO] [stderr]     Checking lazycell v1.3.0
[INFO] [stderr]     Checking unicode-width v0.1.10
[INFO] [stderr]     Checking walkdir v2.3.3
[INFO] [stderr]     Checking number_prefix v0.4.0
[INFO] [stderr]     Checking difference v2.0.0
[INFO] [stderr]     Checking termtree v0.4.1
[INFO] [stderr]     Checking normalize-line-endings v0.3.0
[INFO] [stderr]     Checking home v0.5.4
[INFO] [stderr]     Checking glob v0.3.1
[INFO] [stderr]     Checking predicates-tree v1.0.9
[INFO] [stderr]     Checking aho-corasick v0.7.20
[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" "6c0d36d7ce9552c3ebace255cd6d6cf0bfea7a71b3288d9bd9f84a3679529133", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6c0d36d7ce9552c3ebace255cd6d6cf0bfea7a71b3288d9bd9f84a3679529133", kill_on_drop: false }`
[INFO] [stdout] 6c0d36d7ce9552c3ebace255cd6d6cf0bfea7a71b3288d9bd9f84a3679529133