[INFO] updating cached repository learn-you-a-rust/return_values
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/learn-you-a-rust/return_values
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/learn-you-a-rust/return_values" "work/ex/beta-1.37-6/sources/1.36.0/gh/learn-you-a-rust/return_values"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/1.36.0/gh/learn-you-a-rust/return_values'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/learn-you-a-rust/return_values" "work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/learn-you-a-rust/return_values"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/learn-you-a-rust/return_values'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 909d38d1f4f6cefcc5ba7ce7d8b1454ea4bcabe1
[INFO] sha for GitHub repo learn-you-a-rust/return_values: 909d38d1f4f6cefcc5ba7ce7d8b1454ea4bcabe1
[INFO] validating manifest of learn-you-a-rust/return_values on toolchain 1.36.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of learn-you-a-rust/return_values on toolchain beta-2019-07-23
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing learn-you-a-rust/return_values
[INFO] finished frobbing learn-you-a-rust/return_values
[INFO] frobbed toml for learn-you-a-rust/return_values written to work/ex/beta-1.37-6/sources/1.36.0/gh/learn-you-a-rust/return_values/Cargo.toml
[INFO] started frobbing learn-you-a-rust/return_values
[INFO] finished frobbing learn-you-a-rust/return_values
[INFO] frobbed toml for learn-you-a-rust/return_values written to work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/learn-you-a-rust/return_values/Cargo.toml
[INFO] crate learn-you-a-rust/return_values already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing learn-you-a-rust/return_values against beta-2019-07-23 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-5/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/learn-you-a-rust/return_values:/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" "+beta-2019-07-23" "build" "--frozen"`
[INFO] [stdout] b69df1c022106ef7fadeb8d96c5ea90806a14d66fcac2dca3b2f44017823ca9b
[INFO] running `"docker" "start" "-a" "b69df1c022106ef7fadeb8d96c5ea90806a14d66fcac2dca3b2f44017823ca9b"`
[INFO] [stderr]    Compiling return_values v0.1.0 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.44s
[INFO] running `"docker" "inspect" "b69df1c022106ef7fadeb8d96c5ea90806a14d66fcac2dca3b2f44017823ca9b"`
[INFO] running `"docker" "rm" "-f" "b69df1c022106ef7fadeb8d96c5ea90806a14d66fcac2dca3b2f44017823ca9b"`
[INFO] [stdout] b69df1c022106ef7fadeb8d96c5ea90806a14d66fcac2dca3b2f44017823ca9b
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-5/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/learn-you-a-rust/return_values:/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" "+beta-2019-07-23" "test" "--frozen" "--no-run"`
[INFO] [stdout] afad4c8835fa2b196a1ec2267a7d9d72e15b262509bc67129fccf0478de12c06
[INFO] running `"docker" "start" "-a" "afad4c8835fa2b196a1ec2267a7d9d72e15b262509bc67129fccf0478de12c06"`
[INFO] [stderr]    Compiling return_values v0.1.0 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.43s
[INFO] running `"docker" "inspect" "afad4c8835fa2b196a1ec2267a7d9d72e15b262509bc67129fccf0478de12c06"`
[INFO] running `"docker" "rm" "-f" "afad4c8835fa2b196a1ec2267a7d9d72e15b262509bc67129fccf0478de12c06"`
[INFO] [stdout] afad4c8835fa2b196a1ec2267a7d9d72e15b262509bc67129fccf0478de12c06
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-5/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/learn-you-a-rust/return_values:/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" "+beta-2019-07-23" "test" "--frozen"`
[INFO] [stdout] a4fb6137e0ea5a37068d90b3943986a595ee8ba3824116e8ac5eea47a97b31dc
[INFO] running `"docker" "start" "-a" "a4fb6137e0ea5a37068d90b3943986a595ee8ba3824116e8ac5eea47a97b31dc"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/return_values-67b31a91a4ff7159
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `"docker" "inspect" "a4fb6137e0ea5a37068d90b3943986a595ee8ba3824116e8ac5eea47a97b31dc"`
[INFO] running `"docker" "rm" "-f" "a4fb6137e0ea5a37068d90b3943986a595ee8ba3824116e8ac5eea47a97b31dc"`
[INFO] [stdout] a4fb6137e0ea5a37068d90b3943986a595ee8ba3824116e8ac5eea47a97b31dc