error: unconstrained opaque type
  --> $DIR/issue-86800.rs:33:34
   |
LL | type TransactionFuture<'__, O> = impl '__ + Future<Output = TransactionResult<O>>;
   |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = 


stack backtrace:

error: the compiler unexpectedly panicked. this is a bug.







query stack during panic:
#0 [type_of] computing type of `TransactionFuture::{opaque#0}`
#1 [check_mod_item_types] checking item types in top-level module
#2 [analysis] running analysis passes on this crate
end of query stack