[INFO] updating cached repository bholt/scarlet
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/bholt/scarlet
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/bholt/scarlet" "work/ex/beta-1.38-1/sources/1.37.0/gh/bholt/scarlet"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/bholt/scarlet'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/bholt/scarlet" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bholt/scarlet"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bholt/scarlet'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 52266255bc99d2185fd17282c27b93e3f21cd6bd
[INFO] sha for GitHub repo bholt/scarlet: 52266255bc99d2185fd17282c27b93e3f21cd6bd
[INFO] validating manifest of bholt/scarlet 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 bholt/scarlet 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 bholt/scarlet
[INFO] finished frobbing bholt/scarlet
[INFO] frobbed toml for bholt/scarlet written to work/ex/beta-1.38-1/sources/1.37.0/gh/bholt/scarlet/Cargo.toml
[INFO] started frobbing bholt/scarlet
[INFO] finished frobbing bholt/scarlet
[INFO] frobbed toml for bholt/scarlet written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bholt/scarlet/Cargo.toml
[INFO] crate bholt/scarlet 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/bholt/scarlet/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[INFO] the lockfile is outdated, regenerating it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] [stderr]     Updating git repository `https://github.com/mitsuhiko/redis-rs.git`
[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] [stderr]     Updating git repository `https://github.com/mitsuhiko/redis-rs.git`
[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 bholt/scarlet 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-1/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/bholt/scarlet:/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] eda6c953895504a8b801bb824e3a10b6317df11f837e4b346e81aab43a90be8f
[INFO] running `"docker" "start" "-a" "eda6c953895504a8b801bb824e3a10b6317df11f837e4b346e81aab43a90be8f"`
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]    Compiling ascii v0.9.2
[INFO] [stderr]    Compiling combine v3.8.1
[INFO] [stderr]    Compiling redis v0.11.1-alpha.0 (https://github.com/mitsuhiko/redis-rs.git#c1ce4491)
[INFO] [stderr]    Compiling scarlet v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0596]: cannot borrow `*c` as mutable, as it is behind a `&` reference
[INFO] [stderr]   --> src/main.rs:10:10
[INFO] [stderr]    |
[INFO] [stderr] 9  | fn check(c: &Connection) -> RedisResult<isize> {
[INFO] [stderr]    |             ----------- help: consider changing this to be a mutable reference: `&mut redis::Connection`
[INFO] [stderr] 10 |     try!(c.set("foo", 42));
[INFO] [stderr]    |          ^ `c` is a `&` reference, so the data it refers to cannot be borrowed as mutable
[INFO] [stderr] 
[INFO] [stderr] error[E0596]: cannot borrow `*c` as mutable, as it is behind a `&` reference
[INFO] [stderr]   --> src/main.rs:11:5
[INFO] [stderr]    |
[INFO] [stderr] 9  | fn check(c: &Connection) -> RedisResult<isize> {
[INFO] [stderr]    |             ----------- help: consider changing this to be a mutable reference: `&mut redis::Connection`
[INFO] [stderr] 10 |     try!(c.set("foo", 42));
[INFO] [stderr] 11 |     c.get("foo") as RedisResult<isize>
[INFO] [stderr]    |     ^ `c` is a `&` reference, so the data it refers to cannot be borrowed as mutable
[INFO] [stderr] 
[INFO] [stderr] error[E0596]: cannot borrow `*c` as mutable, as it is behind a `&` reference
[INFO] [stderr]   --> src/main.rs:52:9
[INFO] [stderr]    |
[INFO] [stderr] 51 |     fn set(&self, c: &Connection) -> RedisResult<()> {
[INFO] [stderr]    |                      ----------- help: consider changing this to be a mutable reference: `&mut redis::Connection`
[INFO] [stderr] 52 |         c.hset_multiple(Self::key(self.id), argmap!(
[INFO] [stderr]    |         ^ `c` is a `&` reference, so the data it refers to cannot be borrowed as mutable
[INFO] [stderr] 
[INFO] [stderr] error[E0596]: cannot borrow `c` as mutable, as it is not declared as mutable
[INFO] [stderr]   --> src/main.rs:78:27
[INFO] [stderr]    |
[INFO] [stderr] 65 |     let c = client.get_connection().unwrap();
[INFO] [stderr]    |         - help: consider changing this to be mutable: `mut c`
[INFO] [stderr] ...
[INFO] [stderr] 78 |     let r : Vec<String> = c.hget(User::key(u.id), &["username","first","last"]).unwrap();
[INFO] [stderr]    |                           ^ cannot borrow as mutable
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 4 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0596`.
[INFO] [stderr] error: Could not compile `scarlet`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "eda6c953895504a8b801bb824e3a10b6317df11f837e4b346e81aab43a90be8f"`
[INFO] running `"docker" "rm" "-f" "eda6c953895504a8b801bb824e3a10b6317df11f837e4b346e81aab43a90be8f"`
[INFO] [stdout] eda6c953895504a8b801bb824e3a10b6317df11f837e4b346e81aab43a90be8f