[INFO] crate cargo-release 0.12.0-beta.4 is already in cache
[INFO] extracting crate cargo-release 0.12.0-beta.4 into work/ex/pr-60039-1/sources/master#e305df1846a6d985315917ae0c81b74af8b4e641/reg/cargo-release/0.12.0-beta.4
[INFO] extracting crate cargo-release 0.12.0-beta.4 into work/ex/pr-60039-1/sources/try#99a7498759a22b5684caf798a98b7e90ad9d2443/reg/cargo-release/0.12.0-beta.4
[INFO] validating manifest of cargo-release-0.12.0-beta.4 on toolchain master#e305df1846a6d985315917ae0c81b74af8b4e641
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e305df1846a6d985315917ae0c81b74af8b4e641-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of cargo-release-0.12.0-beta.4 on toolchain try#99a7498759a22b5684caf798a98b7e90ad9d2443
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+99a7498759a22b5684caf798a98b7e90ad9d2443-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing cargo-release-0.12.0-beta.4
[INFO] finished frobbing cargo-release-0.12.0-beta.4
[INFO] frobbed toml for cargo-release-0.12.0-beta.4 written to work/ex/pr-60039-1/sources/master#e305df1846a6d985315917ae0c81b74af8b4e641/reg/cargo-release/0.12.0-beta.4/Cargo.toml
[INFO] started frobbing cargo-release-0.12.0-beta.4
[INFO] finished frobbing cargo-release-0.12.0-beta.4
[INFO] frobbed toml for cargo-release-0.12.0-beta.4 written to work/ex/pr-60039-1/sources/try#99a7498759a22b5684caf798a98b7e90ad9d2443/reg/cargo-release/0.12.0-beta.4/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e305df1846a6d985315917ae0c81b74af8b4e641-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+99a7498759a22b5684caf798a98b7e90ad9d2443-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e305df1846a6d985315917ae0c81b74af8b4e641-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+99a7498759a22b5684caf798a98b7e90ad9d2443-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking cargo-release-0.12.0-beta.4 against try#99a7498759a22b5684caf798a98b7e90ad9d2443 for pr-60039-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-60039-1/worker-2/try#99a7498759a22b5684caf798a98b7e90ad9d2443:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-60039-1/sources/try#99a7498759a22b5684caf798a98b7e90ad9d2443/reg/cargo-release/0.12.0-beta.4:/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=forbid" "-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" "+99a7498759a22b5684caf798a98b7e90ad9d2443-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] c2fa33c07e1694d61924949ad34c5658e98a336364d02d23742b17564909a2f4
[INFO] running `"docker" "start" "-a" "c2fa33c07e1694d61924949ad34c5658e98a336364d02d23742b17564909a2f4"`
[INFO] [stderr]     Checking combine v3.8.1
[INFO] [stderr]     Checking assert_fs v0.11.3
[INFO] [stderr]     Checking cargo_metadata v0.7.4
[INFO] [stderr]     Checking toml_edit v0.1.3
[INFO] [stderr] warning[E0502]: cannot borrow `v` as immutable because it is also borrowed as mutable
[INFO] [stderr]   --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/toml_edit-0.1.3/src/index.rs:55:65
[INFO] [stderr]    |
[INFO] [stderr] 44 |       fn index_or_insert<'v>(&self, v: &'v mut Item) -> &'v mut Item {
[INFO] [stderr]    |                          -- lifetime `'v` defined here
[INFO] [stderr] 45 | /         match *v {
[INFO] [stderr] 46 | |             Item::ArrayOfTables(ref mut vec) => {
[INFO] [stderr] 47 | |                 vec.values.get_mut(*self).expect("index out of bounds")
[INFO] [stderr] 48 | |             }
[INFO] [stderr] 49 | |             Item::Value(ref mut a) if a.is_array() => a
[INFO] [stderr]    | |                         --------- mutable borrow occurs here
[INFO] [stderr] ...  |
[INFO] [stderr] 55 | |             _ => panic!("cannot access index {} in {:?}", self, v),
[INFO] [stderr]    | |                                                                 ^ immutable borrow occurs here
[INFO] [stderr] 56 | |         }
[INFO] [stderr]    | |_________- returning this value requires that `v.0` is borrowed for `'v`
[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[E0502]: cannot borrow `v` as immutable because it is also borrowed as mutable
[INFO] [stderr]   --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/toml_edit-0.1.3/src/index.rs:88:63
[INFO] [stderr]    |
[INFO] [stderr] 70 |       fn index_or_insert<'v>(&self, v: &'v mut Item) -> &'v mut Item {
[INFO] [stderr]    |                          -- lifetime `'v` defined here
[INFO] [stderr] ...
[INFO] [stderr] 77 | /         match *v {
[INFO] [stderr] 78 | |             Item::Table(ref mut t) => t.entry(self).or_insert(Item::None),
[INFO] [stderr] 79 | |             Item::Value(ref mut v) if v.is_inline_table() => {
[INFO] [stderr]    | |                         --------- mutable borrow occurs here
[INFO] [stderr] 80 | |                 &mut v
[INFO] [stderr] ...  |
[INFO] [stderr] 88 | |             _ => panic!("cannot access key {} in {:?}", self, v),
[INFO] [stderr]    | |                                                               ^ immutable borrow occurs here
[INFO] [stderr] 89 | |         }
[INFO] [stderr]    | |_________- returning this value requires that `v.0` is borrowed for `'v`
[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]     Checking cargo-release v0.12.0-beta.4 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 38.18s
[INFO] running `"docker" "inspect" "c2fa33c07e1694d61924949ad34c5658e98a336364d02d23742b17564909a2f4"`
[INFO] running `"docker" "rm" "-f" "c2fa33c07e1694d61924949ad34c5658e98a336364d02d23742b17564909a2f4"`
[INFO] [stdout] c2fa33c07e1694d61924949ad34c5658e98a336364d02d23742b17564909a2f4