hashconsing-0.3.0 beta regression

[est31]

hashconsing version 0.3.0 regressed from stable to beta (full log):

Aug 03 05:13:21.041 INFO blam! |============================|
Aug 03 05:13:21.041 INFO blam! |
Aug 03 05:13:21.041 INFO blam! | Synced
Aug 03 05:13:21.041 INFO blam! |
Aug 03 05:13:21.041 INFO blam! | Running with 4 threads
Aug 03 05:13:21.041 INFO blam! |
Aug 03 05:13:21.041 INFO blam! | 0 | [ 5] app = v3.v0
Aug 03 05:13:21.041 INFO blam! | Thread 1 is done.
Aug 03 05:13:21.041 INFO blam! | 0 | [ 6] app = (v3).v3.v0
Aug 03 05:13:21.041 INFO blam! | Thread 2 is done.
Aug 03 05:13:21.041 INFO blam! | 0 | [ 7] app = (v3).(v3).v3.v0
Aug 03 05:13:21.041 INFO blam! | Thread 4 is done.
Aug 03 05:13:21.041 INFO blam! | 0 | [ 8] app = (v3).v0.(v3).(v3).v3.v0
Aug 03 05:13:21.041 INFO blam! | Thread 3 is done.
Aug 03 05:13:21.041 INFO blam! thread 'synced' panicked at 'assertion failed: `(left == right)`
Aug 03 05:13:21.041 INFO blam!   left: `8`,
Aug 03 05:13:21.041 INFO blam!  right: `7`', src/main.rs:250:4
Aug 03 05:13:21.041 INFO blam! note: Run with `RUST_BACKTRACE=1` for a backtrace.

cc @AdrienChampion

[arielb1]

#42541: the format of assert_eq messages changed. I don't think this is something we are going to guarantee stability on, or revert.

[AdrienChampion]

The hashconsing crate actually had some serious problems before 0.4.0, I strongly suggest you update to the latest version.

[alexcrichton]

Closing as likely a spurious failure due to @AdrienChampion's comment

[AdrienChampion]

I replied too fast, sorry.

The failure is spurious indeed, in the sense that this version of hashconsing is buggy.

For future reference, the problem is that it was using hash for hashconsed term equality, which makes no sense. The failure comes from a hash collision causing two different terms to be equal.