[INFO] updating cached repository Nyrox/Synacor-VM-Challenge
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Nyrox/Synacor-VM-Challenge
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Nyrox/Synacor-VM-Challenge" "work/ex/beta-1.38-1/sources/1.37.0/gh/Nyrox/Synacor-VM-Challenge"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/Nyrox/Synacor-VM-Challenge'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Nyrox/Synacor-VM-Challenge" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Nyrox/Synacor-VM-Challenge"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Nyrox/Synacor-VM-Challenge'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 1c74a23c4b64513cdf882c97438cd94389990dd4
[INFO] sha for GitHub repo Nyrox/Synacor-VM-Challenge: 1c74a23c4b64513cdf882c97438cd94389990dd4
[INFO] validating manifest of Nyrox/Synacor-VM-Challenge 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 Nyrox/Synacor-VM-Challenge 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 Nyrox/Synacor-VM-Challenge
[INFO] finished frobbing Nyrox/Synacor-VM-Challenge
[INFO] frobbed toml for Nyrox/Synacor-VM-Challenge written to work/ex/beta-1.38-1/sources/1.37.0/gh/Nyrox/Synacor-VM-Challenge/Cargo.toml
[INFO] started frobbing Nyrox/Synacor-VM-Challenge
[INFO] finished frobbing Nyrox/Synacor-VM-Challenge
[INFO] frobbed toml for Nyrox/Synacor-VM-Challenge written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Nyrox/Synacor-VM-Challenge/Cargo.toml
[INFO] crate Nyrox/Synacor-VM-Challenge 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 Nyrox/Synacor-VM-Challenge 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-3/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/Nyrox/Synacor-VM-Challenge:/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] e05385e08d358ad47be7e8b93a391ab2efff71f93aaa9650417b1b5b223ef218
[INFO] running `"docker" "start" "-a" "e05385e08d358ad47be7e8b93a391ab2efff71f93aaa9650417b1b5b223ef218"`
[INFO] [stderr]    Compiling synacor 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(exclusive_range_pattern)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(io)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | #![feature(try_from)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::io::prelude::*`
[INFO] [stderr]  --> src/vm.rs:1:5
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::io::prelude::*;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no method named `chars` found for type `std::io::Stdin` in the current scope
[INFO] [stderr]    --> src/vm.rs:213:25
[INFO] [stderr]     |
[INFO] [stderr] 213 |                 let input = stdin().chars().next().unwrap();
[INFO] [stderr]     |                                     ^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 4 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 `synacor`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "e05385e08d358ad47be7e8b93a391ab2efff71f93aaa9650417b1b5b223ef218"`
[INFO] running `"docker" "rm" "-f" "e05385e08d358ad47be7e8b93a391ab2efff71f93aaa9650417b1b5b223ef218"`
[INFO] [stdout] e05385e08d358ad47be7e8b93a391ab2efff71f93aaa9650417b1b5b223ef218