[INFO] updating cached repository xsznix/keygen
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/xsznix/keygen
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/xsznix/keygen" "work/ex/beta-1.38-1/sources/1.37.0/gh/xsznix/keygen"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/xsznix/keygen'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/xsznix/keygen" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/xsznix/keygen"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/xsznix/keygen'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] a622e27e6b4a42b3dcb8259a1e51e882254dcb8c
[INFO] sha for GitHub repo xsznix/keygen: a622e27e6b4a42b3dcb8259a1e51e882254dcb8c
[INFO] validating manifest of xsznix/keygen 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 xsznix/keygen 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 xsznix/keygen
[INFO] finished frobbing xsznix/keygen
[INFO] frobbed toml for xsznix/keygen written to work/ex/beta-1.38-1/sources/1.37.0/gh/xsznix/keygen/Cargo.toml
[INFO] started frobbing xsznix/keygen
[INFO] finished frobbing xsznix/keygen
[INFO] frobbed toml for xsznix/keygen written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/xsznix/keygen/Cargo.toml
[INFO] crate xsznix/keygen 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/xsznix/keygen/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[INFO] the lockfile is outdated, regenerating it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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing xsznix/keygen 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/xsznix/keygen:/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] 38f3d8a7a278bd9c6e98a022b7e6cf82f38e30d869a8e78bcc74a941ef6e44ac
[INFO] running `"docker" "start" "-a" "38f3d8a7a278bd9c6e98a022b7e6cf82f38e30d869a8e78bcc74a941ef6e44ac"`
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]    Compiling unicode-width v0.1.5
[INFO] [stderr]    Compiling getopts v0.2.19
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]    Compiling rand v0.3.23
[INFO] [stderr]    Compiling keygen v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(linked_list_extras)]
[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 `keygen`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "38f3d8a7a278bd9c6e98a022b7e6cf82f38e30d869a8e78bcc74a941ef6e44ac"`
[INFO] running `"docker" "rm" "-f" "38f3d8a7a278bd9c6e98a022b7e6cf82f38e30d869a8e78bcc74a941ef6e44ac"`
[INFO] [stdout] 38f3d8a7a278bd9c6e98a022b7e6cf82f38e30d869a8e78bcc74a941ef6e44ac