[INFO] crate qp-trie 0.7.3 is already in cache
[INFO] extracting crate qp-trie 0.7.3 into work/ex/beta-1.38-1/sources/1.37.0/reg/qp-trie/0.7.3
[INFO] extracting crate qp-trie 0.7.3 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/qp-trie/0.7.3
[INFO] validating manifest of qp-trie-0.7.3 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 qp-trie-0.7.3 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 qp-trie-0.7.3
[INFO] finished frobbing qp-trie-0.7.3
[INFO] frobbed toml for qp-trie-0.7.3 written to work/ex/beta-1.38-1/sources/1.37.0/reg/qp-trie/0.7.3/Cargo.toml
[INFO] started frobbing qp-trie-0.7.3
[INFO] finished frobbing qp-trie-0.7.3
[INFO] frobbed toml for qp-trie-0.7.3 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/qp-trie/0.7.3/Cargo.toml
[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 qp-trie-0.7.3 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-6/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/qp-trie/0.7.3:/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] f2e179d15b404986dfaf0be7b058e78c941255a7a599c3db08829c046f09ca18
[INFO] running `"docker" "start" "-a" "f2e179d15b404986dfaf0be7b058e78c941255a7a599c3db08829c046f09ca18"`
[INFO] [stderr]    Compiling qp-trie v0.7.3 (/opt/crater/workdir)
[INFO] [stderr] warning[E0499]: cannot borrow `*self` as mutable more than once at a time
[INFO] [stderr]    --> src/node.rs:502:41
[INFO] [stderr]     |
[INFO] [stderr] 479 |           &mut self,
[INFO] [stderr]     |           - let's call the lifetime of this reference `'1`
[INFO] [stderr] ...
[INFO] [stderr] 485 | /         match *self {
[INFO] [stderr] 486 | |             Node::Branch(ref mut branch) if branch.choice <= graft => {
[INFO] [stderr]     | |                          -------------- first mutable borrow occurs here
[INFO] [stderr] 487 | |                 let index = branch.index(key.borrow());
[INFO] [stderr] 488 | |
[INFO] [stderr] ...   |
[INFO] [stderr] 502 | |                 let node = mem::replace(self, Node::Branch(Branch::new(graft)));
[INFO] [stderr]     | |                                         ^^^^ second mutable borrow occurs here
[INFO] [stderr] ...   |
[INFO] [stderr] 517 | |             }
[INFO] [stderr] 518 | |         }
[INFO] [stderr]     | |_________- returning this value requires that `self.0` is borrowed for `'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]     = note: for more information, try `rustc --explain E0729`
[INFO] [stderr] 
[INFO] [stderr] warning[E0499]: cannot borrow `*self` as mutable more than once at a time
[INFO] [stderr]    --> src/node.rs:505:45
[INFO] [stderr]     |
[INFO] [stderr] 479 |           &mut self,
[INFO] [stderr]     |           - let's call the lifetime of this reference `'1`
[INFO] [stderr] ...
[INFO] [stderr] 485 | /         match *self {
[INFO] [stderr] 486 | |             Node::Branch(ref mut branch) if branch.choice <= graft => {
[INFO] [stderr]     | |                          -------------- first mutable borrow occurs here
[INFO] [stderr] 487 | |                 let index = branch.index(key.borrow());
[INFO] [stderr] 488 | |
[INFO] [stderr] ...   |
[INFO] [stderr] 505 | |                 let graft_branch = unsafe { self.unwrap_branch_mut() };
[INFO] [stderr]     | |                                             ^^^^ second mutable borrow occurs here
[INFO] [stderr] ...   |
[INFO] [stderr] 517 | |             }
[INFO] [stderr] 518 | |         }
[INFO] [stderr]     | |_________- returning this value requires that `self.0` is borrowed for `'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]     = note: for more information, try `rustc --explain E0729`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.77s
[INFO] running `"docker" "inspect" "f2e179d15b404986dfaf0be7b058e78c941255a7a599c3db08829c046f09ca18"`
[INFO] running `"docker" "rm" "-f" "f2e179d15b404986dfaf0be7b058e78c941255a7a599c3db08829c046f09ca18"`
[INFO] [stdout] f2e179d15b404986dfaf0be7b058e78c941255a7a599c3db08829c046f09ca18
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-6/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/qp-trie/0.7.3:/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" "test" "--frozen" "--no-run"`
[INFO] [stdout] 00c66f441b4574408547ab74a0e0db57a26993a340b417aab21a336ff542e87a
[INFO] running `"docker" "start" "-a" "00c66f441b4574408547ab74a0e0db57a26993a340b417aab21a336ff542e87a"`
[INFO] [stderr]    Compiling unreachable v0.1.1
[INFO] [stderr]    Compiling rand_core v0.2.2
[INFO] [stderr]    Compiling quickcheck v0.7.2
[INFO] [stderr]    Compiling debug_unreachable v0.1.1
[INFO] [stderr]    Compiling qptrie v0.2.4
[INFO] [stderr]    Compiling qp-trie v0.7.3 (/opt/crater/workdir)
[INFO] [stderr] warning[E0499]: cannot borrow `*self` as mutable more than once at a time
[INFO] [stderr]    --> src/node.rs:502:41
[INFO] [stderr]     |
[INFO] [stderr] 479 |           &mut self,
[INFO] [stderr]     |           - let's call the lifetime of this reference `'1`
[INFO] [stderr] ...
[INFO] [stderr] 485 | /         match *self {
[INFO] [stderr] 486 | |             Node::Branch(ref mut branch) if branch.choice <= graft => {
[INFO] [stderr]     | |                          -------------- first mutable borrow occurs here
[INFO] [stderr] 487 | |                 let index = branch.index(key.borrow());
[INFO] [stderr] 488 | |
[INFO] [stderr] ...   |
[INFO] [stderr] 502 | |                 let node = mem::replace(self, Node::Branch(Branch::new(graft)));
[INFO] [stderr]     | |                                         ^^^^ second mutable borrow occurs here
[INFO] [stderr] ...   |
[INFO] [stderr] 517 | |             }
[INFO] [stderr] 518 | |         }
[INFO] [stderr]     | |_________- returning this value requires that `self.0` is borrowed for `'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]     = note: for more information, try `rustc --explain E0729`
[INFO] [stderr] 
[INFO] [stderr] warning[E0499]: cannot borrow `*self` as mutable more than once at a time
[INFO] [stderr]    --> src/node.rs:505:45
[INFO] [stderr]     |
[INFO] [stderr] 479 |           &mut self,
[INFO] [stderr]     |           - let's call the lifetime of this reference `'1`
[INFO] [stderr] ...
[INFO] [stderr] 485 | /         match *self {
[INFO] [stderr] 486 | |             Node::Branch(ref mut branch) if branch.choice <= graft => {
[INFO] [stderr]     | |                          -------------- first mutable borrow occurs here
[INFO] [stderr] 487 | |                 let index = branch.index(key.borrow());
[INFO] [stderr] 488 | |
[INFO] [stderr] ...   |
[INFO] [stderr] 505 | |                 let graft_branch = unsafe { self.unwrap_branch_mut() };
[INFO] [stderr]     | |                                             ^^^^ second mutable borrow occurs here
[INFO] [stderr] ...   |
[INFO] [stderr] 517 | |             }
[INFO] [stderr] 518 | |         }
[INFO] [stderr]     | |_________- returning this value requires that `self.0` is borrowed for `'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]     = note: for more information, try `rustc --explain E0729`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.38s
[INFO] running `"docker" "inspect" "00c66f441b4574408547ab74a0e0db57a26993a340b417aab21a336ff542e87a"`
[INFO] running `"docker" "rm" "-f" "00c66f441b4574408547ab74a0e0db57a26993a340b417aab21a336ff542e87a"`
[INFO] [stdout] 00c66f441b4574408547ab74a0e0db57a26993a340b417aab21a336ff542e87a
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-6/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/qp-trie/0.7.3:/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" "test" "--frozen"`
[INFO] [stdout] 73a2210e7bb13668a6814fab1ffda00ee874388e970d253edc87e6c13d8285bf
[INFO] running `"docker" "start" "-a" "73a2210e7bb13668a6814fab1ffda00ee874388e970d253edc87e6c13d8285bf"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.03s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/qp_trie-d29646dceb6d61f6
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test util::test::nybble ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stderr]      Running /opt/crater/target/debug/deps/lib-7939063c2317e106
[INFO] [stdout] 
[INFO] [stdout] running 20 tests
[INFO] [stdout] test insert_and_get_1 ... ok
[INFO] [stdout] test entry_insert_and_remove_1 ... ok
[INFO] [stdout] test insert_and_get_2 ... ok
[INFO] [stdout] test insert_and_get_3 ... ok
[INFO] [stdout] test insert_and_get_5 ... ok
[INFO] [stdout] test insert_and_get_4 ... ok
[INFO] [stdout] test insert_and_remove_1 ... ok
[INFO] [stdout] test entry_insert_and_remove_2 ... ok
[INFO] [stdout] test longest_common_prefix_complex ... ok
[INFO] [stdout] test longest_common_prefix_simple ... ok
[INFO] [stdout] test prefix_sets_1 ... ok
[INFO] [stdout] test insert_and_get ... ok
[INFO] [stdout] test iter_keys ... ok
[INFO] [stdout] test prefix_sets ... ok
[INFO] [stdout] test iter_values ... ok
[INFO] [stdout] test longest_common_prefix ... ok
[INFO] [stdout] test insert_and_remove ... ok
[INFO] [stdout] test prefix_sets_mut ... ok
[INFO] [stdout] test entry_insert_and_remove ... ok
[INFO] [stdout] test prefix_sets_ref ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 20 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests qp-trie
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test src/trie.rs - trie::Trie (line 25) ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `"docker" "inspect" "73a2210e7bb13668a6814fab1ffda00ee874388e970d253edc87e6c13d8285bf"`
[INFO] running `"docker" "rm" "-f" "73a2210e7bb13668a6814fab1ffda00ee874388e970d253edc87e6c13d8285bf"`
[INFO] [stdout] 73a2210e7bb13668a6814fab1ffda00ee874388e970d253edc87e6c13d8285bf