[INFO] updating cached repository adamreeve/mio-server
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/adamreeve/mio-server
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/adamreeve/mio-server" "work/ex/beta-1.38-1/sources/1.37.0/gh/adamreeve/mio-server"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/adamreeve/mio-server'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/adamreeve/mio-server" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/adamreeve/mio-server"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/adamreeve/mio-server'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 4c8cb526175abc63ca500757e2cd4a5c1dc8e933
[INFO] sha for GitHub repo adamreeve/mio-server: 4c8cb526175abc63ca500757e2cd4a5c1dc8e933
[INFO] validating manifest of adamreeve/mio-server 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 adamreeve/mio-server 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 adamreeve/mio-server
[INFO] finished frobbing adamreeve/mio-server
[INFO] frobbed toml for adamreeve/mio-server written to work/ex/beta-1.38-1/sources/1.37.0/gh/adamreeve/mio-server/Cargo.toml
[INFO] started frobbing adamreeve/mio-server
[INFO] finished frobbing adamreeve/mio-server
[INFO] frobbed toml for adamreeve/mio-server written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/adamreeve/mio-server/Cargo.toml
[INFO] crate adamreeve/mio-server 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/adamreeve/mio-server/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[INFO] the lockfile is outdated, regenerating it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 adamreeve/mio-server 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/adamreeve/mio-server:/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] 97e4df13b98557fa7ec3bb1dcbfd95f80541202cb842aca017370de80cd01ec4
[INFO] running `"docker" "start" "-a" "97e4df13b98557fa7ec3bb1dcbfd95f80541202cb842aca017370de80cd01ec4"`
[INFO] [stderr]    Compiling slab v0.1.3
[INFO] [stderr]    Compiling bytes v0.3.0
[INFO] [stderr]    Compiling ws2_32-sys v0.2.1
[INFO] [stderr]    Compiling memchr v0.1.11
[INFO] [stderr]    Compiling net2 v0.2.33
[INFO] [stderr]    Compiling nix v0.5.1
[INFO] [stderr]    Compiling thread-id v2.0.0
[INFO] [stderr]    Compiling aho-corasick v0.5.3
[INFO] [stderr]    Compiling thread_local v0.2.7
[INFO] [stderr]    Compiling miow v0.1.5
[INFO] [stderr]    Compiling regex v0.1.80
[INFO] [stderr]    Compiling mio v0.5.1
[INFO] [stderr]    Compiling env_logger v0.3.5
[INFO] [stderr]    Compiling mio-server 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(result_expect)]
[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 `mio-server`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "97e4df13b98557fa7ec3bb1dcbfd95f80541202cb842aca017370de80cd01ec4"`
[INFO] running `"docker" "rm" "-f" "97e4df13b98557fa7ec3bb1dcbfd95f80541202cb842aca017370de80cd01ec4"`
[INFO] [stdout] 97e4df13b98557fa7ec3bb1dcbfd95f80541202cb842aca017370de80cd01ec4