[INFO] crate trie 0.2.0 is already in cache
[INFO] extracting crate trie 0.2.0 into work/ex/beta-1.37-6/sources/1.36.0/reg/trie/0.2.0
[INFO] extracting crate trie 0.2.0 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/trie/0.2.0
[INFO] validating manifest of trie-0.2.0 on toolchain 1.36.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of trie-0.2.0 on toolchain beta-2019-07-23
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing trie-0.2.0
[INFO] finished frobbing trie-0.2.0
[INFO] frobbed toml for trie-0.2.0 written to work/ex/beta-1.37-6/sources/1.36.0/reg/trie/0.2.0/Cargo.toml
[INFO] started frobbing trie-0.2.0
[INFO] finished frobbing trie-0.2.0
[INFO] frobbed toml for trie-0.2.0 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/trie/0.2.0/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing trie-0.2.0 against 1.36.0 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-4/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/trie/0.2.0:/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" "+1.36.0" "build" "--frozen"`
[INFO] [stdout] daaa160ea5813c66da229ca59ea31d2c0738d803d097b9b673fd074afb7e6bd1
[INFO] running `"docker" "start" "-a" "daaa160ea5813c66da229ca59ea31d2c0738d803d097b9b673fd074afb7e6bd1"`
[INFO] [stderr]    Compiling bit-vec v0.5.1
[INFO] [stderr]    Compiling bit-set v0.5.1
[INFO] [stderr]    Compiling ordered_iter v0.1.1
[INFO] [stderr]    Compiling trie v0.2.0 (/opt/crater/workdir)
[INFO] [stderr] warning[E0499]: cannot borrow `*start_node` as mutable more than once at a time
[INFO] [stderr]    --> src/map.rs:702:24
[INFO] [stderr]     |
[INFO] [stderr] 674 | fn insert<'a, T>(count: &mut usize, start_node: &'a mut TrieNode<T>, key: usize, value: T, idx: usize)
[INFO] [stderr]     |           -- lifetime `'a` defined here
[INFO] [stderr] ...
[INFO] [stderr] 692 |         External(stored_key, ref mut stored_value) if stored_key == key => {
[INFO] [stderr]     |                              -------------------- first mutable borrow occurs here
[INFO] [stderr] ...
[INFO] [stderr] 695 |             return (stored_value, Some(old_value));
[INFO] [stderr]     |                    ------------------------------- returning this value requires that `start_node.1` is borrowed for `'a`
[INFO] [stderr] ...
[INFO] [stderr] 702 |     match mem::replace(start_node, Internal(Box::new(InternalNode::new()))) {
[INFO] [stderr]     |                        ^^^^^^^^^^ second mutable borrow occurs here
[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] 
[INFO] [stderr] warning[E0503]: cannot use `*start_node` because it was mutably borrowed
[INFO] [stderr]    --> src/map.rs:705:17
[INFO] [stderr]     |
[INFO] [stderr] 674 | fn insert<'a, T>(count: &mut usize, start_node: &'a mut TrieNode<T>, key: usize, value: T, idx: usize)
[INFO] [stderr]     |           -- lifetime `'a` defined here
[INFO] [stderr] ...
[INFO] [stderr] 692 |         External(stored_key, ref mut stored_value) if stored_key == key => {
[INFO] [stderr]     |                              -------------------- borrow of `start_node.1` occurs here
[INFO] [stderr] ...
[INFO] [stderr] 695 |             return (stored_value, Some(old_value));
[INFO] [stderr]     |                    ------------------------------- returning this value requires that `start_node.1` is borrowed for `'a`
[INFO] [stderr] ...
[INFO] [stderr] 705 |                 Internal(ref mut new_node) => {
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^ use of borrowed `start_node.1`
[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] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.60s
[INFO] running `"docker" "inspect" "daaa160ea5813c66da229ca59ea31d2c0738d803d097b9b673fd074afb7e6bd1"`
[INFO] running `"docker" "rm" "-f" "daaa160ea5813c66da229ca59ea31d2c0738d803d097b9b673fd074afb7e6bd1"`
[INFO] [stdout] daaa160ea5813c66da229ca59ea31d2c0738d803d097b9b673fd074afb7e6bd1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-4/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/trie/0.2.0:/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" "+1.36.0" "test" "--frozen" "--no-run"`
[INFO] [stdout] 98c88f2a944b513389b41942c484b982b11d9a24e3f611be2f1e7b3a3441b452
[INFO] running `"docker" "start" "-a" "98c88f2a944b513389b41942c484b982b11d9a24e3f611be2f1e7b3a3441b452"`
[INFO] [stderr]    Compiling trie v0.2.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:13:19
[INFO] [stderr]    |
[INFO] [stderr] 13 | #![cfg_attr(test, feature(fn_traits, step_by, test, unboxed_closures))]
[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 `trie`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "98c88f2a944b513389b41942c484b982b11d9a24e3f611be2f1e7b3a3441b452"`
[INFO] running `"docker" "rm" "-f" "98c88f2a944b513389b41942c484b982b11d9a24e3f611be2f1e7b3a3441b452"`
[INFO] [stdout] 98c88f2a944b513389b41942c484b982b11d9a24e3f611be2f1e7b3a3441b452