[INFO] cloning repository https://github.com/virtustron/regex_research
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/virtustron/regex_research" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvirtustron%2Fregex_research", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvirtustron%2Fregex_research'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f7551cd9ad7ce27481a12ed0606ee41587ea9b26
[INFO] testing virtustron/regex_research against master#cdb45c87e2cd43495379f7e867e3cc15dcee9f93 for pr-145838-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvirtustron%2Fregex_research" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/virtustron/regex_research
[INFO] finished tweaking git repo https://github.com/virtustron/regex_research
[INFO] tweaked toml for git repo https://github.com/virtustron/regex_research written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/virtustron/regex_research on toolchain cdb45c87e2cd43495379f7e867e3cc15dcee9f93
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/virtustron/regex_research 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" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e187383737c8f8b5b0e24f4020ded37860c9c8b7531e47b135f213c3ed400505
[INFO] running `Command { std: "docker" "start" "-a" "e187383737c8f8b5b0e24f4020ded37860c9c8b7531e47b135f213c3ed400505", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e187383737c8f8b5b0e24f4020ded37860c9c8b7531e47b135f213c3ed400505", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e187383737c8f8b5b0e24f4020ded37860c9c8b7531e47b135f213c3ed400505", kill_on_drop: false }`
[INFO] [stdout] e187383737c8f8b5b0e24f4020ded37860c9c8b7531e47b135f213c3ed400505
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b896ac80489293810e209e32f15dc3364e4b526bcd038763d3c5e7adbf384ff9
[INFO] running `Command { std: "docker" "start" "-a" "b896ac80489293810e209e32f15dc3364e4b526bcd038763d3c5e7adbf384ff9", kill_on_drop: false }`
[INFO] [stderr]    Compiling regex v1.5.4
[INFO] [stderr]    Compiling regex_research v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0635]: unknown feature `hash_drain_filter`
[INFO] [stdout]  --> src/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(hash_drain_filter)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `drain_filter` found for struct `HashMap<K, V, S>` in the current scope
[INFO] [stdout]   --> src/main.rs:55:84
[INFO] [stdout]    |
[INFO] [stdout] 55 | ...   let filtered_options: HashMap<String, String> = parsed_options.drain_filter(|k, _v| declined_keys.contains(k)).collect();           
[INFO] [stdout]    |                                                                      ^^^^^^^^^^^^ method not found in `HashMap<String, String>`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0599, E0635.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0599`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `regex_research` (bin "regex_research") due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "b896ac80489293810e209e32f15dc3364e4b526bcd038763d3c5e7adbf384ff9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b896ac80489293810e209e32f15dc3364e4b526bcd038763d3c5e7adbf384ff9", kill_on_drop: false }`
[INFO] [stdout] b896ac80489293810e209e32f15dc3364e4b526bcd038763d3c5e7adbf384ff9