[INFO] cloning repository https://github.com/arons/RustPlaygound
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/arons/RustPlaygound" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farons%2FRustPlaygound", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farons%2FRustPlaygound'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e1a84b400d75127d0db2db3fe0deff41b85803d1
[INFO] checking arons/RustPlaygound against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farons%2FRustPlaygound" "/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/arons/RustPlaygound on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/arons/RustPlaygound
[INFO] finished tweaking git repo https://github.com/arons/RustPlaygound
[INFO] tweaked toml for git repo https://github.com/arons/RustPlaygound written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/arons/RustPlaygound 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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: virtual workspace defaulting to `resolver = "1"` despite one or more workspace members being on edition 2021 which implies `resolver = "2"`
[INFO] [stderr] note: to keep the current resolver, specify `workspace.resolver = "1"` in the workspace root's manifest
[INFO] [stderr] note: to use the edition 2021 resolver, specify `workspace.resolver = "2"` in the workspace root's manifest
[INFO] [stderr] note: for more details see https://doc.rust-lang.org/cargo/reference/resolver.html#resolver-versions
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded num_cpus v1.14.0
[INFO] [stderr]   Downloaded qrcode v0.11.2
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9996fae16be099c361c4272fe9b7e0f164bf6814916cae8e612f1d06e5d43cfe
[INFO] running `Command { std: "docker" "start" "-a" "9996fae16be099c361c4272fe9b7e0f164bf6814916cae8e612f1d06e5d43cfe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9996fae16be099c361c4272fe9b7e0f164bf6814916cae8e612f1d06e5d43cfe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9996fae16be099c361c4272fe9b7e0f164bf6814916cae8e612f1d06e5d43cfe", kill_on_drop: false }`
[INFO] [stdout] 9996fae16be099c361c4272fe9b7e0f164bf6814916cae8e612f1d06e5d43cfe
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 04a0cee91c9c3dfae92dc2a7d9b3e2c21c57f9b5709d0d8e672e379c8cf370f4
[INFO] running `Command { std: "docker" "start" "-a" "04a0cee91c9c3dfae92dc2a7d9b3e2c21c57f9b5709d0d8e672e379c8cf370f4", kill_on_drop: false }`
[INFO] [stderr] warning: virtual workspace defaulting to `resolver = "1"` despite one or more workspace members being on edition 2021 which implies `resolver = "2"`
[INFO] [stderr] note: to keep the current resolver, specify `workspace.resolver = "1"` in the workspace root's manifest
[INFO] [stderr] note: to use the edition 2021 resolver, specify `workspace.resolver = "2"` in the workspace root's manifest
[INFO] [stderr] note: for more details see https://doc.rust-lang.org/cargo/reference/resolver.html#resolver-versions
[INFO] [stderr]    Compiling crossbeam-utils v0.8.12
[INFO] [stderr]    Compiling memoffset v0.6.5
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.11
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling rayon-core v1.9.3
[INFO] [stderr]    Compiling num-integer v0.1.45
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling rayon v1.5.3
[INFO] [stderr]    Compiling num-iter v0.1.43
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]     Checking either v1.8.0
[INFO] [stderr]     Checking num_cpus v1.14.0
[INFO] [stderr]     Checking deflate v0.7.20
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking checked_int_cast v1.0.0
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking png v0.15.3
[INFO] [stderr]     Checking crossbeam-channel v0.5.6
[INFO] [stderr]     Checking crossbeam-deque v0.8.2
[INFO] [stderr]     Checking add_one v0.1.0 (/opt/rustwide/workdir/add_one)
[INFO] [stderr]     Checking lesson v0.1.0 (/opt/rustwide/workdir/lesson)
[INFO] [stderr]     Checking adder v0.1.0 (/opt/rustwide/workdir/adder)
[INFO] [stdout] warning: the item `add_one` is imported redundantly
[INFO] [stdout]  --> adder/src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use add_one;
[INFO] [stdout]   |     ^^^^^^^ the item `add_one` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `add_one` is imported redundantly
[INFO] [stdout]  --> adder/src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use add_one;
[INFO] [stdout]   |     ^^^^^^^ the item `add_one` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling num-derive v0.2.5
[INFO] [stderr]     Checking jpeg-decoder v0.1.22
[INFO] [stderr]     Checking tiff v0.3.1
[INFO] [stderr]     Checking image v0.22.5
[INFO] [stderr]     Checking qrcode v0.11.2
[INFO] [stderr]     Checking barcode v0.1.0 (/opt/rustwide/workdir/barcode)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 8.78s
[INFO] running `Command { std: "docker" "inspect" "04a0cee91c9c3dfae92dc2a7d9b3e2c21c57f9b5709d0d8e672e379c8cf370f4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "04a0cee91c9c3dfae92dc2a7d9b3e2c21c57f9b5709d0d8e672e379c8cf370f4", kill_on_drop: false }`
[INFO] [stdout] 04a0cee91c9c3dfae92dc2a7d9b3e2c21c57f9b5709d0d8e672e379c8cf370f4