[INFO] cloning repository https://github.com/RaginBajin/rustlings
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/RaginBajin/rustlings" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRaginBajin%2Frustlings", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRaginBajin%2Frustlings'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] cc2ea03e14e3a7a4efbe1c2b35b1e68855955234
[INFO] checking RaginBajin/rustlings against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRaginBajin%2Frustlings" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/RaginBajin/rustlings on toolchain ceab6128fa48a616bfd3e3adf4bc80133b8ee223
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/RaginBajin/rustlings
[INFO] finished tweaking git repo https://github.com/RaginBajin/rustlings
[INFO] tweaked toml for git repo https://github.com/RaginBajin/rustlings written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/RaginBajin/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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded predicates v1.0.8
[INFO] [stderr]   Downloaded float-cmp v0.8.0
[INFO] [stderr]   Downloaded serde_derive v1.0.129
[INFO] [stderr]   Downloaded predicates-tree v1.0.3
[INFO] [stderr]   Downloaded argh_shared v0.1.5
[INFO] [stderr]   Downloaded argh_derive v0.1.5
[INFO] [stderr]   Downloaded argh v0.1.5
[INFO] [stderr]   Downloaded escargot v0.4.0
[INFO] [stderr]   Downloaded terminal_size v0.1.17
[INFO] [stderr]   Downloaded serde v1.0.129
[INFO] [stderr]   Downloaded syn v1.0.75
[INFO] [stderr]   Downloaded libc v0.2.100
[INFO] [stderr]   Downloaded indicatif v0.16.2
[INFO] [stderr]   Downloaded filetime v0.2.15
[INFO] [stderr]   Downloaded assert_cmd v0.11.1
[INFO] [stderr]   Downloaded home v0.5.3
[INFO] [stderr]   Downloaded console v0.15.0
[INFO] [stderr]   Downloaded predicates-core v1.0.2
[INFO] [stderr]   Downloaded proc-macro2 v1.0.28
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 197b8c0f55bd41fe5120bfac2e00eaaf826fc36681c4c88db2f270a8351e2550
[INFO] running `Command { std: "docker" "start" "-a" "197b8c0f55bd41fe5120bfac2e00eaaf826fc36681c4c88db2f270a8351e2550", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "197b8c0f55bd41fe5120bfac2e00eaaf826fc36681c4c88db2f270a8351e2550", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "197b8c0f55bd41fe5120bfac2e00eaaf826fc36681c4c88db2f270a8351e2550", kill_on_drop: false }`
[INFO] [stdout] 197b8c0f55bd41fe5120bfac2e00eaaf826fc36681c4c88db2f270a8351e2550
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bde57711162be63baa27703964decc765ef22db6c37cac65376f7adc3f36178a
[INFO] running `Command { std: "docker" "start" "-a" "bde57711162be63baa27703964decc765ef22db6c37cac65376f7adc3f36178a", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.100
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.75
[INFO] [stderr]    Compiling memchr v2.4.1
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling serde_derive v1.0.129
[INFO] [stderr]    Compiling serde v1.0.129
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]    Compiling serde_json v1.0.81
[INFO] [stderr]     Checking itoa v1.0.2
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]     Checking slab v0.4.4
[INFO] [stderr]    Compiling unicode-segmentation v1.8.0
[INFO] [stderr]     Checking predicates-core v1.0.2
[INFO] [stderr]     Checking once_cell v1.10.0
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]    Compiling escargot v0.4.0
[INFO] [stderr]    Compiling argh_shared v0.1.5
[INFO] [stderr]     Checking number_prefix v0.4.0
[INFO] [stderr]     Checking treeline v0.1.0
[INFO] [stderr]     Checking difference v2.0.0
[INFO] [stderr]     Checking home v0.5.3
[INFO] [stderr]     Checking predicates-tree v1.0.3
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]     Checking aho-corasick v0.7.18
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking net2 v0.2.37
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking terminal_size v0.1.17
[INFO] [stderr]     Checking inotify-sys v0.1.5
[INFO] [stderr]     Checking filetime v0.2.15
[INFO] [stderr]     Checking inotify v0.7.1
[INFO] [stderr]     Checking float-cmp v0.8.0
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]     Checking mio-extras v2.0.6
[INFO] [stderr]     Checking regex v1.5.5
[INFO] [stderr]     Checking notify v4.0.17
[INFO] [stderr]     Checking console v0.15.0
[INFO] [stderr]     Checking predicates v1.0.8
[INFO] [stderr]     Checking indicatif v0.16.2
[INFO] [stderr]    Compiling argh_derive v0.1.5
[INFO] [stderr]     Checking argh v0.1.5
[INFO] [stderr]     Checking toml v0.5.9
[INFO] [stderr]     Checking rustlings v5.4.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking assert_cmd v0.11.1
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 7.83s
[INFO] running `Command { std: "docker" "inspect" "bde57711162be63baa27703964decc765ef22db6c37cac65376f7adc3f36178a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bde57711162be63baa27703964decc765ef22db6c37cac65376f7adc3f36178a", kill_on_drop: false }`
[INFO] [stdout] bde57711162be63baa27703964decc765ef22db6c37cac65376f7adc3f36178a
[INFO] checking RaginBajin/rustlings against try#3a4bc97f6385a3aa300a4fd689b44350e54fd676 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRaginBajin%2Frustlings" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/RaginBajin/rustlings on toolchain 3a4bc97f6385a3aa300a4fd689b44350e54fd676
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/RaginBajin/rustlings
[INFO] finished tweaking git repo https://github.com/RaginBajin/rustlings
[INFO] tweaked toml for git repo https://github.com/RaginBajin/rustlings written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/RaginBajin/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" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 55927457c4faaf0dcd4abe274e8ddfd3f656f1cfec360bd12a6af34c749982a3
[INFO] running `Command { std: "docker" "start" "-a" "55927457c4faaf0dcd4abe274e8ddfd3f656f1cfec360bd12a6af34c749982a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "55927457c4faaf0dcd4abe274e8ddfd3f656f1cfec360bd12a6af34c749982a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "55927457c4faaf0dcd4abe274e8ddfd3f656f1cfec360bd12a6af34c749982a3", kill_on_drop: false }`
[INFO] [stdout] 55927457c4faaf0dcd4abe274e8ddfd3f656f1cfec360bd12a6af34c749982a3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 23084477958ad446e765e870f452a4d7fe11be47ea329551c6fde2686a51a737
[INFO] running `Command { std: "docker" "start" "-a" "23084477958ad446e765e870f452a4d7fe11be47ea329551c6fde2686a51a737", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.100
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.75
[INFO] [stderr]    Compiling memchr v2.4.1
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling serde_derive v1.0.129
[INFO] [stderr]    Compiling serde v1.0.129
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling serde_json v1.0.81
[INFO] [stderr]     Checking slab v0.4.4
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]     Checking itoa v1.0.2
[INFO] [stderr]    Compiling unicode-segmentation v1.8.0
[INFO] [stderr]    Compiling escargot v0.4.0
[INFO] [stderr]    Compiling argh_shared v0.1.5
[INFO] [stderr]     Checking lazycell v1.3.0
[INFO] [stderr]     Checking once_cell v1.10.0
[INFO] [stderr]     Checking predicates-core v1.0.2
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]     Checking walkdir v2.3.2
[INFO] [stderr]     Checking difference v2.0.0
[INFO] [stderr]     Checking treeline v0.1.0
[INFO] [stderr]     Checking number_prefix v0.4.0
[INFO] [stderr]     Checking predicates-tree v1.0.3
[INFO] [stderr]     Checking home v0.5.3
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]     Checking aho-corasick v0.7.18
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking net2 v0.2.37
[INFO] [stderr]     Checking inotify-sys v0.1.5
[INFO] [stderr]     Checking terminal_size v0.1.17
[INFO] [stderr]     Checking filetime v0.2.15
[INFO] [stderr]     Checking inotify v0.7.1
[INFO] [stderr]     Checking float-cmp v0.8.0
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]     Checking mio-extras v2.0.6
[INFO] [stderr]     Checking regex v1.5.5
[INFO] [stderr]     Checking notify v4.0.17
[INFO] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/regex-1.5.5/src/exec.rs:848:13
[INFO] [stdout]     |
[INFO] [stdout] 848 | /             match dfa::Fsm::reverse(
[INFO] [stdout] 849 | |                 &self.ro.dfa_reverse,
[INFO] [stdout] 850 | |                 self.cache.value(),
[INFO] [stdout] 851 | |                 false,
[INFO] [stdout] ...   |
[INFO] [stdout] 862 | |                 Quit => return Some(Quit),
[INFO] [stdout] 863 | |             };
[INFO] [stdout]     | |_____________^ cannot infer type
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0282`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `regex` (lib) due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "23084477958ad446e765e870f452a4d7fe11be47ea329551c6fde2686a51a737", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "23084477958ad446e765e870f452a4d7fe11be47ea329551c6fde2686a51a737", kill_on_drop: false }`
[INFO] [stdout] 23084477958ad446e765e870f452a4d7fe11be47ea329551c6fde2686a51a737