stack backtrace:

error: internal compiler error: unexpected panic









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