[INFO] updating cached repository jtianling/toc-auto-add
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/jtianling/toc-auto-add
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/jtianling/toc-auto-add" "work/ex/beta-1.38-1/sources/1.37.0/gh/jtianling/toc-auto-add"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/jtianling/toc-auto-add'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/jtianling/toc-auto-add" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jtianling/toc-auto-add"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jtianling/toc-auto-add'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 95c05965d9d58cb6207521e97d5ad0fa428d3131
[INFO] sha for GitHub repo jtianling/toc-auto-add: 95c05965d9d58cb6207521e97d5ad0fa428d3131
[INFO] validating manifest of jtianling/toc-auto-add on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of jtianling/toc-auto-add on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing jtianling/toc-auto-add
[INFO] finished frobbing jtianling/toc-auto-add
[INFO] frobbed toml for jtianling/toc-auto-add written to work/ex/beta-1.38-1/sources/1.37.0/gh/jtianling/toc-auto-add/Cargo.toml
[INFO] started frobbing jtianling/toc-auto-add
[INFO] finished frobbing jtianling/toc-auto-add
[INFO] frobbed toml for jtianling/toc-auto-add written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jtianling/toc-auto-add/Cargo.toml
[INFO] crate jtianling/toc-auto-add already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] error: the lock file /mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/jtianling/toc-auto-add/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing jtianling/toc-auto-add against 1.37.0 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-0/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/jtianling/toc-auto-add:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+1.37.0" "build" "--frozen"`
[INFO] [stdout] c7d1602c2b562dd1bf3dcba8df836da14b75e88c5183ec82c528b8a9a6304e49
[INFO] running `"docker" "start" "-a" "c7d1602c2b562dd1bf3dcba8df836da14b75e88c5183ec82c528b8a9a6304e49"`
[INFO] [stderr]    Compiling toc-auto-add v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0599]: no method named `at` found for type `regex::Captures<'_>` in the current scope
[INFO] [stderr]   --> src/main.rs:56:77
[INFO] [stderr]    |
[INFO] [stderr] 56 |       let title_string: &str = first_level_title_re.captures(line).unwrap().at(1).unwrap();
[INFO] [stderr]    |                                                                             ^^
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no method named `at` found for type `regex::Captures<'_>` in the current scope
[INFO] [stderr]   --> src/main.rs:66:78
[INFO] [stderr]    |
[INFO] [stderr] 66 |       let title_string: &str = second_level_title_re.captures(line).unwrap().at(1).unwrap();
[INFO] [stderr]    |                                                                              ^^
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no method named `at` found for type `regex::Captures<'_>` in the current scope
[INFO] [stderr]    --> src/main.rs:123:81
[INFO] [stderr]     |
[INFO] [stderr] 123 |     let title_area_string: &str = title_area_re.captures(file_content).unwrap().at(2).unwrap();
[INFO] [stderr]     |                                                                                 ^^
[INFO] [stderr] 
[INFO] [stderr] error[E0308]: mismatched types
[INFO] [stderr]    --> src/main.rs:131:12
[INFO] [stderr]     |
[INFO] [stderr] 118 | fn add_or_replace_toc(file_content: &str, toc: &str) -> String {
[INFO] [stderr]     |                                                         ------ expected `std::string::String` because of return type
[INFO] [stderr] ...
[INFO] [stderr] 131 |     return replaced_file_content;
[INFO] [stderr]     |            ^^^^^^^^^^^^^^^^^^^^^ expected struct `std::string::String`, found enum `std::borrow::Cow`
[INFO] [stderr]     |
[INFO] [stderr]     = note: expected type `std::string::String`
[INFO] [stderr]                found type `std::borrow::Cow<'_, str>`
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no method named `at` found for type `regex::Captures<'_>` in the current scope
[INFO] [stderr]    --> src/main.rs:140:85
[INFO] [stderr]     |
[INFO] [stderr] 140 |     let more_comment_string: &str = more_comment_re.captures(file_content).unwrap().at(0).unwrap();
[INFO] [stderr]     |                                                                                     ^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 5 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0308, E0599.
[INFO] [stderr] For more information about an error, try `rustc --explain E0308`.
[INFO] [stderr] error: Could not compile `toc-auto-add`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "c7d1602c2b562dd1bf3dcba8df836da14b75e88c5183ec82c528b8a9a6304e49"`
[INFO] running `"docker" "rm" "-f" "c7d1602c2b562dd1bf3dcba8df836da14b75e88c5183ec82c528b8a9a6304e49"`
[INFO] [stdout] c7d1602c2b562dd1bf3dcba8df836da14b75e88c5183ec82c528b8a9a6304e49