[INFO] updating cached repository davidbegin/messing-with-mods
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/davidbegin/messing-with-mods
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/davidbegin/messing-with-mods" "work/ex/beta-1.38-1/sources/1.37.0/gh/davidbegin/messing-with-mods"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/davidbegin/messing-with-mods'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/davidbegin/messing-with-mods" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/davidbegin/messing-with-mods"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/davidbegin/messing-with-mods'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 4af51b287f1e7d3f73874f22ccc108deeb5bf96a
[INFO] sha for GitHub repo davidbegin/messing-with-mods: 4af51b287f1e7d3f73874f22ccc108deeb5bf96a
[INFO] validating manifest of davidbegin/messing-with-mods 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 davidbegin/messing-with-mods 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 davidbegin/messing-with-mods
[INFO] finished frobbing davidbegin/messing-with-mods
[INFO] frobbed toml for davidbegin/messing-with-mods written to work/ex/beta-1.38-1/sources/1.37.0/gh/davidbegin/messing-with-mods/Cargo.toml
[INFO] started frobbing davidbegin/messing-with-mods
[INFO] finished frobbing davidbegin/messing-with-mods
[INFO] frobbed toml for davidbegin/messing-with-mods written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/davidbegin/messing-with-mods/Cargo.toml
[INFO] crate davidbegin/messing-with-mods 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] error: the lock file /mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/davidbegin/messing-with-mods/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[INFO] the lockfile is outdated, regenerating it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] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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 davidbegin/messing-with-mods 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-5/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/davidbegin/messing-with-mods:/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] 529a36749385bb3f04cf8fb2523fa3e69a02a21918141c12ac5c4257fcbda4b5
[INFO] running `"docker" "start" "-a" "529a36749385bb3f04cf8fb2523fa3e69a02a21918141c12ac5c4257fcbda4b5"`
[INFO] [stderr]    Compiling dirs-sys v0.3.4
[INFO] [stderr]    Compiling dirs v2.0.2
[INFO] [stderr]    Compiling term v0.6.1
[INFO] [stderr]    Compiling messin_with_mods v0.0.1 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(rustc_private)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `messin_with_mods`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "529a36749385bb3f04cf8fb2523fa3e69a02a21918141c12ac5c4257fcbda4b5"`
[INFO] running `"docker" "rm" "-f" "529a36749385bb3f04cf8fb2523fa3e69a02a21918141c12ac5c4257fcbda4b5"`
[INFO] [stdout] 529a36749385bb3f04cf8fb2523fa3e69a02a21918141c12ac5c4257fcbda4b5