[INFO] updating cached repository Coneko/stack
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Coneko/stack
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Coneko/stack" "work/ex/beta-1.38-1/sources/1.37.0/gh/Coneko/stack"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/Coneko/stack'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Coneko/stack" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Coneko/stack"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Coneko/stack'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 184a8d91e18b204b5e3eaa859b9ffb4c9ac0e05a
[INFO] sha for GitHub repo Coneko/stack: 184a8d91e18b204b5e3eaa859b9ffb4c9ac0e05a
[INFO] validating manifest of Coneko/stack 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 Coneko/stack 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 Coneko/stack
[INFO] finished frobbing Coneko/stack
[INFO] frobbed toml for Coneko/stack written to work/ex/beta-1.38-1/sources/1.37.0/gh/Coneko/stack/Cargo.toml
[INFO] started frobbing Coneko/stack
[INFO] finished frobbing Coneko/stack
[INFO] frobbed toml for Coneko/stack written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Coneko/stack/Cargo.toml
[INFO] crate Coneko/stack 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 Coneko/stack 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-7/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/Coneko/stack:/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] ef434bb0b6257552eb3578db84d7cbd8614a4150a511f732ac374a7c537662d6
[INFO] running `"docker" "start" "-a" "ef434bb0b6257552eb3578db84d7cbd8614a4150a511f732ac374a7c537662d6"`
[INFO] [stderr]    Compiling openssl v0.9.23
[INFO] [stderr]    Compiling num-traits v0.1.42
[INFO] [stderr]    Compiling unindent v0.1.2
[INFO] [stderr]    Compiling cmake v0.1.29
[INFO] [stderr]    Compiling openssl-sys v0.9.24
[INFO] [stderr]    Compiling libz-sys v1.0.18
[INFO] [stderr]    Compiling rand v0.3.20
[INFO] [stderr]    Compiling curl-sys v0.4.1
[INFO] [stderr]    Compiling clap v2.29.2
[INFO] [stderr]    Compiling mio v0.6.12
[INFO] [stderr]    Compiling tokio-io v0.1.4
[INFO] [stderr]    Compiling serde_derive_internals v0.19.0
[INFO] [stderr]    Compiling url v1.6.0
[INFO] [stderr]    Compiling regex v0.2.5
[INFO] [stderr]    Compiling indoc-impl v0.2.3
[INFO] [stderr]    Compiling libssh2-sys v0.2.6
[INFO] [stderr]    Compiling libgit2-sys v0.7.1
[INFO] [stderr]    Compiling backtrace v0.3.5
[INFO] [stderr] warning[E0713]: borrow may still be in use when destructor runs
[INFO] [stderr]    --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/url-1.6.0/src/form_urlencoded.rs:261:40
[INFO] [stderr]     |
[INFO] [stderr] 259 | impl<'a> Target for ::UrlQuery<'a> {
[INFO] [stderr]     |      -- lifetime `'a` defined here
[INFO] [stderr] 260 |     fn as_mut_string(&mut self) -> &mut String { &mut self.url.serialization }
[INFO] [stderr] 261 |     fn finish(self) -> &'a mut ::Url { self.url }
[INFO] [stderr]     |                                        ^^^^^^^^ - here, drop of `self` needs exclusive access to `*self.url`, because the type `UrlQuery<'_>` implements the `Drop` trait
[INFO] [stderr]     |                                        |
[INFO] [stderr]     |                                        returning this value requires that `*self.url` is borrowed for `'a`
[INFO] [stderr]     |
[INFO] [stderr]     = warning: this error has been downgraded to a warning for backwards compatibility with previous releases
[INFO] [stderr]     = warning: this represents potential undefined behavior in your code and this warning will become a hard error in the future
[INFO] [stderr]     = note: for more information, try `rustc --explain E0729`
[INFO] [stderr] 
[INFO] [stderr]    Compiling serde_json v1.0.9
[INFO] [stderr]    Compiling tempfile v2.2.0
[INFO] [stderr]    Compiling indoc v0.2.3
[INFO] [stderr]    Compiling error-chain v0.11.0
[INFO] [stderr]    Compiling tokio-core v0.1.12
[INFO] [stderr]    Compiling serde_derive v1.0.27
[INFO] [stderr]    Compiling tokio-proto v0.1.1
[INFO] [stderr]    Compiling hyper v0.11.16
[INFO] [stderr]    Compiling native-tls v0.1.5
[INFO] [stderr]    Compiling tokio-tls v0.1.4
[INFO] [stderr]    Compiling hyper-tls v0.1.2
[INFO] [stderr]    Compiling hubcaps v0.4.3
[INFO] [stderr]    Compiling git2 v0.7.1
[INFO] [stderr]    Compiling stack v0.0.1 (/opt/crater/workdir)
[INFO] [stderr] warning: unused `#[macro_use]` import
[INFO] [stderr]  --> src/lib.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | #[macro_use]
[INFO] [stderr]   | ^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[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(nll)]
[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 `stack`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "ef434bb0b6257552eb3578db84d7cbd8614a4150a511f732ac374a7c537662d6"`
[INFO] running `"docker" "rm" "-f" "ef434bb0b6257552eb3578db84d7cbd8614a4150a511f732ac374a7c537662d6"`
[INFO] [stdout] ef434bb0b6257552eb3578db84d7cbd8614a4150a511f732ac374a7c537662d6