[INFO] cloning repository https://github.com/AJTJ/rust_problems
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/AJTJ/rust_problems" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAJTJ%2Frust_problems", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAJTJ%2Frust_problems'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 87f258cdf9eab9b23a01bba18486cecee34b3f8b
[INFO] testing AJTJ/rust_problems against beta-2021-08-01 for beta-1.55-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAJTJ%2Frust_problems" "/workspace/builds/worker-14/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-14/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/AJTJ/rust_problems on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/AJTJ/rust_problems
[INFO] finished tweaking git repo https://github.com/AJTJ/rust_problems
[INFO] tweaked toml for git repo https://github.com/AJTJ/rust_problems written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] crate git repo https://github.com/AJTJ/rust_problems already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "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-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] df8eaa08c736b17a5288bf3adc8eaadfe2657f8d13692715a85788e1e4f45a63
[INFO] running `Command { std: "docker" "start" "-a" "df8eaa08c736b17a5288bf3adc8eaadfe2657f8d13692715a85788e1e4f45a63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "df8eaa08c736b17a5288bf3adc8eaadfe2657f8d13692715a85788e1e4f45a63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "df8eaa08c736b17a5288bf3adc8eaadfe2657f8d13692715a85788e1e4f45a63", kill_on_drop: false }`
[INFO] [stdout] df8eaa08c736b17a5288bf3adc8eaadfe2657f8d13692715a85788e1e4f45a63
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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=warn" "-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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 075844be820754a2ab3bfdf3f462479eb367dfa0d7f5b91ce5d7e30520223701
[INFO] running `Command { std: "docker" "start" "-a" "075844be820754a2ab3bfdf3f462479eb367dfa0d7f5b91ce5d7e30520223701", kill_on_drop: false }`
[INFO] [stderr] Compiling rust_problems v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0277]: cannot add `Option