[INFO] updating cached repository silversupreme/reckon
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/silversupreme/reckon
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/silversupreme/reckon" "work/ex/beta-1.38-1/sources/1.37.0/gh/silversupreme/reckon"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/silversupreme/reckon'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/silversupreme/reckon" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/silversupreme/reckon"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/silversupreme/reckon'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 1f31eb6ef6455b21d35fac53fbb4470315d5100f
[INFO] sha for GitHub repo silversupreme/reckon: 1f31eb6ef6455b21d35fac53fbb4470315d5100f
[INFO] validating manifest of silversupreme/reckon 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 silversupreme/reckon 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 silversupreme/reckon
[INFO] finished frobbing silversupreme/reckon
[INFO] frobbed toml for silversupreme/reckon written to work/ex/beta-1.38-1/sources/1.37.0/gh/silversupreme/reckon/Cargo.toml
[INFO] started frobbing silversupreme/reckon
[INFO] finished frobbing silversupreme/reckon
[INFO] frobbed toml for silversupreme/reckon written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/silversupreme/reckon/Cargo.toml
[INFO] crate silversupreme/reckon 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] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing silversupreme/reckon 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/silversupreme/reckon:/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] 06c7daed75958ca417cbc664f41b86067053c09a432ae84b2525a94be7216c5f
[INFO] running `"docker" "start" "-a" "06c7daed75958ca417cbc664f41b86067053c09a432ae84b2525a94be7216c5f"`
[INFO] [stderr]    Compiling thread-id v2.0.0
[INFO] [stderr]    Compiling thread_local v0.2.7
[INFO] [stderr]    Compiling regex v0.1.80
[INFO] [stderr]    Compiling reckon v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:9:1
[INFO] [stderr]   |
[INFO] [stderr] 9 | #![feature(io)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no method named `chars` found for type `&mut std::process::ChildStdout` in the current scope
[INFO] [stderr]    --> src/base.rs:154:28
[INFO] [stderr]     |
[INFO] [stderr] 154 |         let mut c = stdout.chars();
[INFO] [stderr]     |                            ^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0554, E0599.
[INFO] [stderr] For more information about an error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `reckon`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "06c7daed75958ca417cbc664f41b86067053c09a432ae84b2525a94be7216c5f"`
[INFO] running `"docker" "rm" "-f" "06c7daed75958ca417cbc664f41b86067053c09a432ae84b2525a94be7216c5f"`
[INFO] [stdout] 06c7daed75958ca417cbc664f41b86067053c09a432ae84b2525a94be7216c5f